Robert Bell 09/05/1980

This site is dedicated to experiments in audio-visual moving image and constructions in 3D virtual space. It contains notes on surrounding theories and processes.

Friday 13 June 2008

VIEWING

To view the Final Composition here is a link to the course website......

http://www.mgc08.com/

I will post photographs of the show viewing up on the blog but here is a 3d model of how I envisage the piece to look and at what scale it should be presented at.

The next step would be to turn it into an interactive viewing interface, this could incorporate many separate animations on screen at the same time.

The project would work best as an interface, it would no longer simply be an audio-visual animation, the screen would turn into something to investigate up close with the viewer choosing what to explore and at what point.

FINAL PIECE ELEMENTS



Front Elevation Reading with Audio




Perspective Reading



Perspective Reading with added relief map extrusions

Sunday 8 June 2008

EVALUATION

The final project pieces will not be posted up here but I will reflect on them and the project as a whole none the less. I am pleased with the completion of the task. It was a great exercise in methods and processes and taught me alot about the simple act of timing, rendering and most importantly I feel project organisation.

The simpler the outcome got the happier I was as I feel I have produced an 'honest' result to my brief. It may seem that not a great deal was achieved in terms of animation but this project iwas I feel very large in terms of management and preparation..

At times the proposal was not central to my thinking and this slowed the project down as I forgot the main aim of the whole thing. A shame considering the writing of the proposal was a very useful exercise and the part that although initially struggling with, I actuallly enjoyed immensely.

It is very difficult to clearly state why you want to do something and then how!

Stylistically the result is somewhere in the middle. Interestingly minimal but at the same time too conservative in approach. To me though it is still an 'animatic' or test piece, a working out of ideas in one technology that can then be followed through with more imagination.

It has definately helped me with 3D software skills, not in terms of modelling, texturing etc but in terms of new approaches to form generation and dealing with time and sequence, areas that I will try to incorporate into wider architectural visualisation.

I have not really had the time to see this through to an installation or interactive outcome, but this is the next step. I am content to realise this. This I feel is the major learning to come from the last term, that nothing comes easy in this field, and that only through hard work and alot of hours do results show themselves. I struggled at many times to get to the next stage mainly because working with computers can lack a sense of scale and immediacy that I get from other mediums.

I have pushed myself to do thorough research and the hidden benefit of such projects is all the little bits of new information that you pick up along the way, even if they dont immediately inform your work. I now know about stereoscopy, the history of the phone exchange, how to make your own dialtones and obviously alot more about a building in Vauxhall.

It is a shame that this has to end now as I only just feel that the project has got to that brilliant stage when it becomes malleable and decisions feel intuitive. Obviously I would do things differently if going over again, but I feel that I have got alot out of the system and can now move on with a clearer focus.

Although not a convert to purely deterministic approaches to projects I have noved away from trying to pre-judge outcomes and getting confused with simply trying to visualise an 'image' that I feel may look impressive.

The next project that I undertake will be more interesting as a result I'm sure.

RESONANCE

The next step is to bring the readings to life and to add greater dynamism and visual intrigue to the piece, at the moment they are too flat and lifeless. They are dealing with frequencies but hardly move. Each element has to have its own motion frequency as well.

I have been looking into sound frequencies but animation itself has a frequency. A frame rate of 30fps resonates at 33.3 milliseconds and has a frequency of 30hz. Here are a few other examples that will inform my next step.

1ms = flash strobe light
2.27ms = 440hz (tuning device)
50ms = 20hz (lowest frequency of human recognition)
100ms = blink of an eye/reaction speed of a human.
150ms = time delay for a telephone service
200-670ms = general beat of modern dance music

With this in mind we can determine the frame rate for each the window tones:

Tone range = 20-100hz
= 50ms-10ms

Therefore a brightness level of 100% (100hz) = 10ms = one one hundredth of a second.

We would have to render are animation at 100 frames per second however to achieve this result.

40hz = 25ms = one fourtieth of a second = 40 fps
50hz = 20ms = one fiftieth of a second =50fps

This is very difficult to achieve in reality but we can achieve the effect of resonance nonetheless.

This next study is rendered at 50fps and has the tones resonating at 50hz. In other words the elements go through a cycle of being visable and not present.

Note that having some elements stay constant highlights the resonating elements.

The optical result I feel will play on the desired sense of secrecy and conspiracy that I wanted fromthe outset.


Because of the playback device the result is inconsistant, sometimes frames are dropped that are present at other time sof viewing.

BACK TO 3D

I realise that both perspective and elevational representations have there benefits.

The bass flicker animations highlight the variation in tone very well and also the shadow causing the secondary visual beat is clear to read. For analysis of the tones in three dimensions they give us less however.

Rendering the model in perspective and also with camera movement is what is needed, it also adds greater dynamic to the animations.

Audio will be added, but for now here is a perspective animation showing a reading of the top two floors.

BASS FLICKER ANIMATIONS

Reading each tone individually floor by floor gives a detailed analysis of the site but produces a fairly slow paced animation. I feel that it would be great to see and hear the building in a faster paced fashion. The next two experiments contain a render of each floor as a still with audio containing all the frequencies together as one sound. These are then animated in sequence.

The result is an interesting stop motion reading of the facade as a whole simulating a graphic equalizer on a stereo.

Left side:

Right Side:

AUDIO EXPERIMENTS 3 : Bass + Melody

Here is the resulting audio for the top floor with both tracks played together.

AUDIO EXPERIMENTS 2 : Melody

Having decided on 11 sections per side (10 window tones plus dial tone), I now need do build a melody for the track. This I want to be varying but also personal to the individual. Therefore I have decided to use the dial tone frequencies that make up touch tone phones (numbers 0-9).

These consist of dual frequency tones, getting higher in frequency from 0-9. You can see a table of the frequencies through an earlier link in the 'DIALTONES' post.

To match up with the 11 sections I will use the sequence for mobile phone numbers. Here is the resulting audio for my mobile number, played twice.

AUDIO EXPERIMENTS 1

I feel that I must pay equal attention to the audio so as not to produce a conceptually misleading result.

I will use the window tones to program the sound as well as the forms of the animation. The window tones will form one part of the audio, the low frequency track (bass tones), and I will use dial tone frequencies to produce the higher frequency audio (melody).

Concentrating on the bass track first here are the audio results for the top three floors, read from left to right.


They were made by taking the brightness level for each window and converting them straight into a single frequency (67% brightness = 67hz).

The tone duration is dependant on whether it is a wide or narrow window section (long or short tone as with dial tones!). This means that each floor will follow the same beat rhythm of short and long sections and therefore result in a musical composition.

The audio tempo follows the tempo that I have rendered the visuals, if we say a narrow window is one section and a wide one two, each side contains 10 sections, each floor 20 overall . I will make one section half a second (15 frames), so 10 seconds per floor.

An addition at the beginning and end of each floor is an added tone (Dial tone 425hz0, signifying a working line is operating. I will use this to signify a change of floor level.

The changes are subtle for sure but when listened to together in one track will produce an interesting mutating bass line.

Friday 6 June 2008

LEFT / RIGHT SYMMETRY

Taking the idea of the mirror image of the facade into account I have decided to read both the left and right side of the building using only one structural composition. The tones are read from left to right for the left hand side of the facade and then back again from right to left for the right hand side. This back and forth motion produces a stable constant reading.

The animation below shows the reading of the top floor of the tower.

TONE TEMPO

The animation below shows the window tones per floor for the left side of the facade, animated from top to bottom, followed by the equivalent for the right hand side.

The tempo is fast but highlights the fact that at two points per floor the tone stays constant. It also shows that the right hand side is a mirror image of the left in terms of structure.


ANIMATED WINDOW TONES 1

Having developed a way of turning the towers windows into a visual beat I now need a way to read them, animate them and to turn them into an audio accompaniment.

Here are a few initial considerations:

  1. How to show which tone is being read and how many to read at one time.
  2. Which view to show the window tones in (Front-on, perspective, top plan etc.)
  3. At what tempo the tones are to be read and does this tempo change at all.
Below is a reel of animated studies I produced to help answer these questions.




The first test has the tones as invisible but reads them using a render bar to show up the forms. This I feel is effective in highlighting the undercover nature of the building.

The next two has the tones as semi-transparent but varies the viewing angle.

The final three explore differing camera views and projections but also vary the lighting within the scene. I have animated the light source to move up to replicate the suns movement over the building. This has the effect of altering the shadows cast by the tones and therefore producing a secondary visual beat in the tones and on the bottom level of tones.

This is something that I will investigate further as it could be used to alter volume for example.

The tempo reads the section in 3 seconds and I feel may be too fast.

PROCESS ANIMATION

Here is a small animation showing exactly how the relief mapping results in varied 3D form. At frame zero the 'Top level' is set to 0% and steadily increases to 100%. Note that most of the movement occurs in a very short time, this is due to the fact that the levels in the relief map are very close together in value.

Window tones Relief mapping

The next experiment I undertook was to put the window tones into the relief map for the top 2 floors. All of the windows lie somewhere between the 0% of the glazing and 100% of the cladding. The variation in levels produces a visual beat for the facade.

Below is the relief map for the top floor


Below is the resulting C4D relief model

Thursday 29 May 2008

Window tones


  • Looking at the building again, I realise that I can read more into the elevation than first meets the eye. Relief mapping can be used to produce accuracy but also to re-interpret!
  • The windows on Keybridges facade all contain blinds to block out the outside world, these are all of a muted green or blue shade. each window therefore has its own level of brightness and therefore its own position on a relief model.
1) Each window could be read as a dial tone, as there are ten dial tones for numbers (0-9) we could assign each 'brightness level 10 percentile' a tone. The facade could then be read as a series of numbers each triggering a particular tone.
  • This study shows the brightness levels for each of the main windows on the facade. Note that each floor is made up of three glazed sections however.
  • The lowest section contains only one consistant tone as it is made up one repeated colour, From the ground level it is impossible to see how this works on the very top few floors however.
  • The top window section is usually in shadow caused by the overhanging concrete slab and it is difficult to read as a level. I will take advantage of this fact in some way I'm sure!

I am going to start by concentrating my experiments on the middle section.

Relief Mapping experiments

The 3d modelling I wish to use for this project relies on the process of using relief mapping to read 2d images and turn them into 3D virtual constructs. Cinema 4D does this very efficiently and renders them fairly quickly and accurately.

The first experiment I carried out was to model the front elevation with accuracy using the depth measurements taken on site and from photographs.

Relief mapping works by reading an images levels of brightness and converting them into positions of depth.

White= 100% brightness= furthest forward on the relief map Black= 0% brightness= furthest back on the relief map

Any levels in between get placed accordingly.

The element of the facade nearest you is the metal vertical cladding running up the building (equals white 100%).

The element furthest from you is the glazing (equals black 0%).

The distance between the two is 1500mm, setting the relief map to this then allows me to calculate the levels required for accurately positioning all other elements.

The concrete slab needs a level of brightness = 35%

These levels are applied to the CAD drawing in photoshop in greyscale. Below is the initial relief map for the top eight floors.



Here is the new relief map of 1 floor only and the resulting C4D facade.


Initial 3D Modelling

Although I don't want this to be a normal architectural modelling exercise, I still believe any outcomes should come from an accurate reading of the buildings structure. From the site photographs and drawings/measurements I have drawn the towers front elevation (front being the one facing South Lambeth Rd) in Vectorworks as a 2D line drawing.

This was a useful exercise as it also showed how the being is made from various elements or units that fit into one another to particular ratios. It also highlighted any changes in the buildings elevational rhythm as you progress down the facade.

I have decided to concentrate solely on the front facade and to read it floor by floor from top to bottom.

Attached firstly is a photo of the facade with workings out and notes drawn on. The second image shows the black and white resulting CAD drawing (top eight floors only for now).

Thursday 15 May 2008

CHECKLIST

Before going further I would like to make a list of the main areas of interest to work on both visually and conceptually. This will guide the graphic nature of the project....

1. Keybridge 'emerges from the ground', or is 'dumped from above'= vertical motion.
2. Rumoured to be 'as deep as it is tall', (soundwave?)
3. Questionable purpose.
4. Building is 'hiding a secret' = shadowy tone.
5. Repetitive nature = tempo.
6. Link to audio frequencies through (disconnected) dial tones.
7. Faceless facade (barrier) vs information flow.
8. Reflection of community.

VISUAL APPROACH RESEARCH 2

I DO NOT LOVE NYC
Very simple visuals with a great feel to them, plus relevant audio.
http://www.youtube.com/watch?v=gaZv3JUxuTA

CITY SCAN#3 - Hfr-Lab
Love this style (rotated view) which matches my survey film nicely!
http://www.youtube.com/watch?v=2N24NLrYKRY

CITY ESCAPE-Parts 1,2
Similar style to Hfr-lab, but a little overdone I feel.
http://www.youtube.com/watch?v=BV8c2Wg-E8w
http://www.youtube.com/watch?v=MArTNJfrIX4

VISUAL MUSIC - Amon Tobin music video
Referenced for its 3D modelling and animation of buildings (2.00/2.40mins)
http://www.youtube.com/watch?v=KFBJNH9LJ24&feature=related

DIAL TONES

When searching for an appropriate audio accompaniment I need look no further than the buildings role as BT phone exchange. It is perfect, it makes sense conceptually.

I have linked some pages below that give an overview of exchanges, dial tones and SIT signals.

http://en.wikipedia.org/wiki/Telephone_exchange
http://en.wikipedia.org/wiki/Dial_tone
http://en.wikipedia.org/wiki/Special_information_tone

Especially relevant are the special information tones, indicating that a call cannot be completed but also automatically classifying why it has failed (e.g. number disconnected, circuits busy, mis-dialing,etc). This feeds into the disconnection of the building, yet maybe not its secrecy. This could be played upon however (mis-information)?

I like the idea that you can develop simple variations in sequence using only two frequencies and two durations (high/low, long/short). The connection to the x and z axis are clear, y could be for volume or loudness?

These tones are usually followed by a recorded voice message explaining the call failure. this introduces an option of a human element into my soundtrack (possibly... secrets, confessions or simply opinions on Keybridge house?).

This could be one way to comment on the building and its communication context?
http://www.youtube.com/watch?v=EFWcAkxzkv4&NR=1

The role as phone exchange also introduces another side to this project, that this building is connected to the outside world, in fact massively, randomly even inter-dependantly. Information maybe streaming in and out constantly through the ground and all around in the air. If the main structure of my motion graphics piece is physical and architectural the second layer can be less tangible, more fluid.

I am reminded of the excellent light sculptures of liktfaktor.....

http://www.lichtfaktor.eu/
http://www.youtube.com/watch?v=dtBJETFfgyY

Now go back and watch the film I took of Keybridge house again. Time to develop a stylistic approach to this project.

Wednesday 14 May 2008

SITE SURVEY-LANCE

I want to get inside this building, maybe not literally, but I want to get beneath its surface to unearth its hidden cycles, to read it in as many ways as possible.

On saturday morning I went to do the first of possibly many site surveys. This incorporated general photograhic documentation of the overall building and a second more structured set of photographs recording the ground floor elevation at eye level (two sides of what I will term the square 'block', as against the 'tower').

I suppose this will give me a better understanding not only of construction but also of the materials used and their general state. These have been pieced together to form the first 'strip' of information.

Secondly it has given me a firmer idea of the buildings beat or rhythm. This was reinforced by filming the same stretch at walking pace at eye level again. Not only in its elevational 'frequency' but also in how the structural elements protrude away or towards the facade, its 'amplitude'.

This information will be read in the way that I have discussed the visualisation of sound in earlier blogs. There has to be a way to read the buildings structure and translate to audio, a link that makes sense and 'becomes the buildings voice'.

I AM NOT ALONE / CONSPIRACY THEORIES


When I got home that night I was after some information.....

Not knowing the name of the building at this point I searched on the net for 'ugly building south lambeth rd', this is where the project started to get interesting for me.

It seems I am not the only one with a strange fascination for Keybridge House. I found forums where fans discuss, articles of hatred from journalists, petitions to sign from local residents and wonderfully, theories of conspiracy surrounding its real purpose.

Keybridge House is owned by BT and is down as one of its phone exchanges, or at least was until recently, it is not exactly sure how in use it is at the moment. I read that no one is really seen entering or emerging except for the odd black car driving from the car park underneath the tower. Visitors report tight security and concealed corridors!

With the M16 building just down the road some believe this to be the real centre of surveillance. It is believed that tunnels may lead from underground to other parts and that the building is as deep as it is tall!

Photographs:
http://flickr.com/photos/27568422@N00/sets/72157604082190139/show/
http://www.flickr.com/photos/benpatio/125636392/
WikiMap:
http://wikimapia.org/5841339/Keybridge_House
Forums:
http://www.archiseek.com/content/showthread.php?t=2353&goto=nextoldest
http://tradescant.blogspot.com/2008/01/is-this-ugliest-office-in-britain.html
Articles:
http://observer.guardian.co.uk/review/story/0,,2233130,00.html

KEYBRIDGE HOUSE




"Keybridge house is a piece of faceless brutalist architecture situated on South Lambeth Rd just west of Vauxhall. Walking past it last week on thursday I saw it and said that it was either the ugliest building in london or the most beautiful?

Not beauty in the correct sense of the term, but a building of interest and emotion non the less. I immediately had a desire to discover it, to document it and fundamentally to animate it!

It had a immense, monstrous approach to the world without a care for its position on the street.

Looking at it further the reasons for this became clearer, there were no signs of any life inside the building, no human in sight either in the grounds, at the reception or either at any of the monotonously filthy windows. In fact you could hardly see into any of the windows in any case as they all are covered by dirty, broken old blinds. The concrete slabs between floors stained and the vertical metal cladding running all the way up the building severe and oversized.

My next observation was that unlike most buildings the facade of this building does not change from pavement to sky, the ground floor has no extra architectural consideration at all. It is like it has simply emerged from underground or been dumped from above.

It is repetitive to the extreme, as you walk round it is as if the building is turning away from you, keeping a secret hidden?"

Thursday 24 April 2008

Inaudible Cities:Part One


Inaudible Cities:Part One

"The first in a series of short films where cities are made of and controlled by sound. In this episode, every detail of an urban landscape is built by the sonic pressures of an oncoming electrical storm. The very fabric of this isolated world is defined by the noises and frequencies that surround a space in another aural dimension. Semiconductor wrote a program which listens to the various parts of the soundtrack and constructs the animated environments."

Watching the quicktime extracts I realise that the key to making this project work is to let it be guided by exploration and experimentation and not to worry too much about the final look of the piece. Also that it could consist of a few seperate mini-pieces each with a varying feel or tone.

Wednesday 23 April 2008

Stylistic approaches



This test piece animation shows how I could display a musical sequence in three dimensions taking advantage of the perception of depth through the computer models use of x,y,z co-ordinates.

If increased amplitude in a soundwave denotes increase in volume we could say that as objects move away from the x axis they increase in volume also. Therefore the rotating concrete blocks are smoothly getting quiter and louder. Care must be taken to get the lighting correct to reinforce this (not successful in this animation).

To take this further, each time the blocks rotate round to the front this will correspond to a period of compression in the sound wave, when lying flat along the horizontal plane this will relate to a state of equilibrium in the wave and when situated furthest away from the camera a period of rarefraction.

Devices to show volume increase could also include variations in colour (warm to cold) or in luminance/glow (light to dark), the latter shown here by the varying glow of the yellow areas.

In terms of a sounds frequency (how often it goes through its cycle per unit of time), this relates to the objects x dimension and how often the object appears in a set x distance. We can introduce ratios of frequencies (2:1 etc) that relate to musical composition.

Further to this a given frequency must be situated logically on the z axis, with higher frequencies at the top and lower frequencies (i:e bass) at the bottom . Higher frequencies with the same volume as low frequencies however usually appear louder so may be pushed forward towards the camera.

I believe this will give my compositions a unified feel and an interesting 'weighting'. This will determine choice of material also, with denser materials (concrete) used at the base.

Interference here is indicated by the shadow variations caused as the result of the motion of two separate elements. This is an element of the process which interests me greatly but is hardest to plan for.

VISUAL RESEARCH 1:Related Practitioners

Some interesting pieces of sound controlled 3D modelling/virtual worlds, cheers Pete!


SEMICONDUCTOR:
http://www.semiconductorfilms.com/root/sonic_inc/sonic_inc.htm

Wow!
....this is the ideal. I just want to have a go myself. I like the real-time aspect of the work and the way that the technology is there not to produce slick photo realistic forms but to be effective and natural. The audio is something which feels intrinsically linked, not a soundtrack but a recording. By dealing with simple audio (resonance) they can achieve a conceptually sound outcome.

ALEX RUTTERFORD:
  • His most well-known works include the videos for "Gantz Graf" by Autechre, "Verbal" by Amon Tobin and "Go to Sleep" by Radiohead. All these videos consist of 3D computer generated imagery, and feature visuals that follow the rhythm of the music very closely.

GANTZ GRAF:











Gantz Graf at the official Warp discography (features audio clips).
http://www.warprecords.com/ography/release.php?cat=WAP256#

NME review of Gantz Graf
http://www.nme.com/reviews/autechre/6602
  • The music video for "Gantz Graf" reached a cult status in underground computer-generated imagery art circles. The video features an abstract object (or an agglomeration of objects) synchronized to the sounds in the music as it morphs, pulsates, shakes, and finally dissolves.
  • The visuals contain the same amount of richness and detail as the soundtrack does, having a visual counterpart to every little sound or frequency range in the song.
Interview with Alex Rutterford in making the "Gantz Graf" video.
http://www.warprecords.com/news/?ti_id=512

Reading the above interview was very valuable to me, with many insights into the process Rutterford took, notably how long and repetitve it was, not relying on a computer algorithym to do the work. It has given me confidence and motivation to attempt something similar.

He also warns that the creative process is a bit like a drug and that the buzz can wear off half way through a project, but that when you finish you want to start all over again. This is the feeling I want at the end, this is the beginning of something, and therefore what is most important is to develop a method of working that excites me and works for me!


Sound based light installation:
http://www.aether.hu/images/distributedprojection/index.html

This guy must be so hard working, his methodical approach to experiments is to be admired.
http://www.carstennicolai.com/?c=works&w=bitwave
http://www.carstennicolai.com/?c=works&w=fades
http://www.umatic.nl/tonewheels_historical.html

Project Brief: Related quotes

Interaction in the perception ("process of attaining awareness or understanding of sensoryinformation ") and cognition ("understanding and trying to make sense of the world") of musical beats and visual beats.

"Beats are the
periodic and repeating fluctuations heard in the intensity of a sound when two sound waves of very similar frequencies interfere with one another."

"Music is a complex organization of sounds harmonizing together to produce a single composition. Similarly,
architecture is a complex yet harmonious organization of space."

"My goal was to explore the physiological (
the compositional) and the psychological (the emotional) implications of designing space around aural perceptions to create a harmonized environment."

"SOUND HAS PHYSICAL SIZE, DIMENSIONS, DENSITY, VIBRANCY, RHYTHMS AND TEXTURES." -BRANDON LABELLE

"THE IDEA IS TO CREATE A WORLD FOR THE AUDIENCE TO ENTER WHERE ARCHITECTURE MAGNIFIES THE EXPRESSIVE DIMENSIONS OF MUSIC AND SOUND."
-ELIZABETH MARTIN

"THE RESULT IS NEITHER PURELY MUSICAL NOR ARCHITECTURAL, BUT A
HYBRID THAT FALLS BETWEEN THE TWO DISCIPLINES."
-ELIZABETH MARTIN

"A moving image is a signal that continuosly change in time. More than forms, figures and volumes, it is made of
dimensions, frequencies, intensities. On a digital medium image and sound share the same substance: electronic coded impulses."

"A new kind of connection is emerging. Now it is possible to create
interactions, driven by mathematical rules, between the audible and the visible media in a way that erodes the barrier between the two fields of sound and image."

"The composer chooses a body of
raw materials (in this case, the bass line that implies melody, harmony, rhythm and gesture), and deepens the understanding of that material by exaggerating, expanding, coloring, limiting, twisting, breaking or reframing the original material, in a series of ordered sequences."

Sound theory Revision



To start this project off it is back to school for me with some 'science of sound' revision, reminds me of the old GCSE days!

To understand the nature and make up of sound I have found it useful to do some research into the theory behind soundwaves (pitch, frequencies, intensity and Decibel levels).

This led to further research into the phenomenon of interference (constructive and destructive) and its relevance to the composition of music most notably beat patterns.

I will not repeat all of the science on this blog but have linked the sites used and pasted some of the diagrams included that I found useful.

I feel that this initial research will prove the foundation of future investigations and am confident that now I have a much better understanding of what it is I am actually trying to replicate in vision and motion.

Wave theory and sound characteristics:
http://www.glenbrook.k12.il.us/gbssci/phys/Class/sound/u11l1a.html
http://www.school-for-champions.com/science/sound.htm

Musical Intervals and scales:
http://kaibd.com/music.html#Intervals