Tag: API

EchoNest segment analysis player in Max

The Echonest API provides sample level audio analysis.

http://developer.echonest.com/docs/v4/_static/AnalyzeDocumentation.pdf

What if you used that data to reconstruct music by driving a sequencer in Max? The analysis is a series of time based quanta called segments. Each segment provides information about timing, timbre, and pitch – roughly corresponding to rhythm, harmony, and melody.

download

https://github.com/tkzic/internet-sensors

folder: echo-nest

files

main Max patch
  • echonest-synth4.maxpat
abstractions and other files
  • polyvoice-sine.maxpat
  • polyvoice2.maxpat
ruby server
  • echonest-synth2.rb

authentication

You will need to sign up for a developer account at The Echo Nest, and get an API key. https://developer.echonest.com

Edit the ruby server file: echonest-synth2.rb replacing the API with your new API from echonest

 

installing ruby gems

Install the following ruby gems (from the terminal):

gem install patron

gem install osc-ruby

gem install json

gem install uri

instructions

1. In Terminal run the ruby server:

./echonest-synth2.rb

2. Open the Max patch: echonest-synth4.maxpat and turn on the audio.

3. Enter an Artist and Song title for analysis, in the text boxes. Then press the greet buttons for title and artist. Then press the /analyze button. If it works you will get prompts from the terminal window, the Max window, and you should see the time in seconds in upper right corner of the patch.

If there are problems with the analysis, its most likely due to one of the following:

  • artist or title spelled incorrectly
  • song is not available
  • song is too long
  • API is busy
If the ruby server hangs or crashes, just restart it and try again.

3. Press one of the preset buttons to turn on the tracks.

4. Now you can play the track by pressing the /play button.

The Mixer channels from Left to right are:

  • bass
  • synth (left)
  • synth (right)
  • random octave synth
  • timbre synth
  • master volume
  • gain trim
  • HPF cutoff frequency
You can also adjust the reverb decay time and the playback rate. Normal playback rate is 1.

programming notes

Best results happen with slow abstract material, like the Miles (Wayne Shorter) piece above. The bass is not really happening. Lines all sound pretty much the same. I’m thinking it might be possible to derive a bass line from the pitch data by doing a chordal analysis of the analysis.

Here are screenshots of the Max sub-patches (the main screen is in the video above)

Timbre (percussion synth) – plays filtered noise:

Random octave synth:

Here’s a Coltrane piece, using roughly the same configuration but with sine oscillators for everything:

There are issues with clicks on the envelopes and the patch is kind of a mess but it plays!

Several modules respond to the API data:

  • tone synthesiszer (pitch data)
  • harmonic (random octave) synthesizer (pitch data)
  • filtered noise (timbre data)
  • bass synthesizer (key and mode data)
  • envelope generator (loudness data)

Since the key/mode data is global for the track, bass notes are probable guesses. This method doesn’t work for material with strong root motion or a variety of harmonic content. Its essentially the same approach I use when asked to play bass at an open mic night.

The envelopes click at times – it may be due to the relaxed method of timing, i.e.., none at all. If they don’t go away when timing is corrected, this might get cleaned up by adding a few milliseconds to the release time – or looking ahead to make sure the edges of  segments are lining up.

[update] Using the Max [poly~] object cleared up the clicking and distortion issues.

Timbre data drives a random noise filter machine. I just patched something together and it sounded responsive – but its kind of hissy – an LPF might make it less interesting.

Haven’t used any of the beat, tatum, or section data yet. The section data should be useful for quashing monotony.

another update – 4/2013

tried to write this into a Max4Live device – so that the pitch data would be played my a Midi (software) instrument. No go. The velocity data gets interpreted in mysterious ways – plus each instrument has its own envelope which interferes with the segment envelopes. Need to think this through. One idea would be to write a device which uses EN analysis data for beats to set warp markers in Live. It would be an amazing auto-warp function for any song. Analysis wars: Berlin vs. Somerville.

Web Audio Playground Max, Osc, and WebSockets

updated 5/17/2014

overview

This fork adds the following features to Chris Wilson’s Web Audio Playground:

  • basic patch load/save capability
  • clipboard copy/paste to get patches in and out of browser
  • OSC control of all parameters using web sockets and a ruby server.

Try it out at: http:zerokidz.com/wap/index.html

For optimum results try Chrome on Mac OS. But it does work in other browsers.

Patch file format is JSON. Patches are reloaded by firing gesture events which created them.

download

Source code: https://github.com/tkzic/WebAudio

files

sub-folder: osctest

Instructions for Osc, Websockets Max/MSP example

Note: You can either run a local web server, using nodeserver.js and index.html – in the WebAudio folder – or use the online version of WAP as described here.

1.  Load WAP in a Google Chrome browser using the following URL: http:zerokidz.com/wap/index.html

2. In WAP, load a patch called: delay-thing.

Note: If the patch doesn’t exist you can paste it in by opening the file osctest/delay-thing.json in a text editor and copying the text. Then click paste in WAP and paste in the text. Then make sure to save it in WAP by typing in the name “delay-thing” and clicking the save-as: button

3. In a terminal window, go to the osctest/ folder and start the server by typing:

ruby ./wapOSCserver.rb

4. In WAP, Press the OSC button – the ruby server should acknowledge with the message: “WebSocket connection open”

5. Open the Max patch: wapOSCtester.maxpat

6. In WAP press the play button on the Oscillator module (you should hear sounds)

7. In the Max patch drag the slider on the left to control the oscillator pitch. You should hear the sound change and see the sliders move in WAP.

Notes on Web Sockets connection:

The html side of the connection is done in js/socketsOSC.js

look at the function: connectOSC() – which gets triggered by the OSC button in index.html

Incoming messages from Max (via Ruby server) are parsed in parseOSCMessage() which figures out how to set appropriate values for the audio objects in the DOM.

There are currently no acknowledgement or error messages being returned (at least I don’t remember doing this)

hardware control of webaudio API

programming

This is a tweak of a demo program by Boris Smus from http://webaudioapi.com

The audio is generated in the web browser using the webaudio API. Oscillator frequency is being controlled by an iPod touch running touchOSC.

A ruby program is running in the background. It starts 2 servers, one to handle Osc messages from the iPod. and a websockets server which passes Osc messages to the web client in the browser, which parses the data and sets oscillator frequency.

local source files in tkzic/web-audio-api/webaudioapi/content/posts/oscillator-ws

instructions

(these are for my local files – source has not been published yet) Please contact me directly for more information about this code. Or have a look at a very similar example at: https://github.com/tkzic/WebAudio

1. run the node webserver in tkzic/

node nodeserver.js

(it will run on localhost port 8081 – for example http://127.0.0.1:8081)

2. In Chrome web browser, run: http://192.168.1.104:8081/web-audio-api/webaudioapi/content/posts/oscillator-ws/index.html

The following screen will appear:

3. From a terminal prompt run this ruby script (in tkzic/web-audio-api/webaudioapi/content/posts/oscillator-ws)

./wapOSCserver.rb

4. In webpage in Chrome, click the sockets button – the ruby server should open a socket connection, also click the play/pause button to start the oscillator

5. In touchOSC point the host to the ip address of the laptop (ie., 192.168.1.104) running on default ports, (out 8000, in 9000)

6. In touchOSC run the ‘simple’ layout and move fader1 to change the pitch of the oscillator

Note: You will probably also want to open the developer javascript console in Chrome to see what is going on.

next step

Need to clean up the ruby server code to handle error conditions, ie., network interruptions, missing files, browser incompatibility, etc.,