Sonification of Mass Ave buses, from Nubian to Harvard.
Updated for Max8 and Catalina
This patch requests data from MBTA API to get the current location of buses – using the Max js object. Latitude and Longitude data is mapped to oscillator pitch. Data is polled every 10 seconds, but it seems like the results might be more interesting to poll at a slower rate, because the updates don’t seem that frequent. And buses tend to stop a lot.
This project uses version 3 of the API. There are quality issues with the realtime data. For example, there are bus stops not associated with the route. The direction_id and stop_sequence data from the buses is often wrong. Also, buses that are not in service are not removed from the vehicle list or indicated as such.
The patch uses a [multislider] object to graph the position of the buses along the route – but due to the data problems described above, the positions don’t always reflect the current latitude/longitude coordinates or the bus stop name.
You will need to replace the API key in the message object at the top of the patch with your own key. Or you can probably just remove it. The key distributed with the patch is fake. You can request your own developer API key from MBTA. It’s free.
instructions
Open mbta.maxpat
Open the Max console window so you can see what’s happening with the data
click on the yellow [getstops] message to get the current bus stop data
Toggle the metro (at the top of the patch) to start polling
Turn on the audio (click speaker icon) and turn up the gain
Note: there will be more buses running during rush hours in Boston. Try experimenting with the polling rate and ramp length in the poly-oscillator patch. Also, you can experiment with the pitch range.
The Soundcloud client-id is embedded in scnode.js – you will need to edit this file to replace the worthless client-id with your own. To get a client ID you will first need a Soundcloud account. Then register an app at: http://soundcloud.com/you/apps
first time instructions
Open the Max patch: sc.maxpat
In the green panel, click on [script npm init]
In the green panel , click on [script install soundcloud-api-client]
instructions
Open the Max patch sc.maxpat
open the max.console window so you can see the API data
click [script start]
click the speaker icon to start audio
type something into the search box and press <enter> or click the button to the left to search for what is already in the box.
select a track from the result menu, wait for it to download and start playing
This implementation uses node.js for Max instead of Ruby to access the API. You will need set up a developer account with Spotify and request API credentials. See below.
Other than that, the synthesis code in Max has not changed. Some of the following background information and video is from the original version. ..
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.
Edit spot1.js replacing the cliendID and clientSecret with your spotify credentials
node for max install instructions (first time only)
Open the Max patch: spotify-synth1.maxpat
Scroll the patch over to the far right side until you see this green panel:
Click the [script npm init] message – this initializes the node infrastructure in the current folder
Then click each of the 2 script npm install messages – this installs the necessary libraries
Instructions
Open the Max patch: spotify-synth1.maxpat
Click the green [script start] message
Click the Speaker icon to start audio
Click the first dot in the preset object to set the mixer settings to something reasonable
open the Max Console window so you can see the Spotify API data
From the 2 menus at the top of the screen select an Artist and Title that match, for example: Albert Ayler and “Witches and Devils”
Click the [analyze] button – the console window should fill with interest data about your selection.
Click [play]
Note: if you hear a lot of clicks and pops, reduce the audio sample rate to 44.1 KHz.
Alternative search method:
Enter an Artist and Song title for analysis, in the text boxes. Then press the 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.
troubleshooting
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
Mixer controls
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. It’s essentially the same approach I use when asked to play bass at an open mic night.
additional notes
Now that this project is running again. I plan to write additional synthesizers that follow more of the spirit of the data. For example, distinguishing strong pitches from noise.
Also would like to make use of the [section] data as well as the rhythmic analysis. There is an amazing amount of potential here.
NOTE: There’s a problem with [shell] – it rejects input that is converted to a symbol using [tosymbol].
This can be fixed by using from symbol – or just eliminating [tosymbol] – it make affect the stderr-stdout redirection token, ie., “>” and other special characters but for now [shell] does not accept symbol input
aka.speech can be replaced using the “say” command in the shell. more details to follow about voice parameters.
‘say’ has similar params to aka.speech, eg., voice name and rate. There are voices for specific languages. This feature could be used, for example, to match the language from a Tweet to an appropriate voice
3. Twitter streaming API
I revised the php code for the Twitter streaming project, to use the coordinates of a corner of the city polygon bounding box. That seems to be more reliable than the geo coordinates which are absent from most Tweets.
There is a new API in the works – but its difficult to decipher the Twitter API docs because they have so many products and the documentation is obtuse.
Also it would be interesting to extract the “language” field and use it to select which voice to use in the speech synthesizer. Or even have an english translation option.
4. Echonest API
Echonest was absorbed into Spotify. The API is gone. But the Spotify API does have some of the feature detection and analysis code. But it doesn’t allow you to submit your own audio clips. There are also some efforts to preserve some of the Echonest stuff like the blog by Paul Lamere, and the remix code. Here are a few links I found to get started.
Inside the Ruby code, change “oauth_token” to “access_token” and “oauth_token_secret” to “access_token_secret”
The streaming client example code failed and I replaced it with a filter that looks for tweets from a twitter id. To get your twitter id, go to https://tweeterid.com/
This patch has been completely re-written. The old API was obsolete. This version uses [dict] and [maxurl] to format and execute the initial query. Then it uses [jit.uldl] to download the mp3 file with the bird-call audio. Interesting that [maxurl] would not download the file using the “download” URL. It only worked with a URL containing the actual file name.
9. ping
Needed to reinstall ruby gems using xcrun (see above)
seems to be a problem with mashape:
Could not resolve host: igor-zachetly-ping-uin.p.mashape.com (Patron::HostResolutionError)
[mashape was acquired by rapidapi.com – so will need to refactor the code in the ruby server.]
“Commissioned for the BBC’s make it digital event, the brief was ‘to get children into code’. My installation downloaded the event’s twitter feed in real time and displayed the page’s body text inside the bodies of passing people. Moving their hands around allowed people to scroll through the html/js/CSS.”
Get track analysis data for your music using the Echonest API.
The track analysis includes summary information about a track including tempo, key signature, time signature mode, danceability, loudness, liveness, speechinesss, acousticness and energy along with detailed information about the song structure (sections) beat structure (bars, beats tatums) and detailed info about timbre, pitch and loudness envelope (segment).
Its a two (or three) step process. Here’s an example of how to upload your track and get an audio summary, using curl from the command line in Mac OS. Note, you will need to register with Echonest to get a developer API key here: http://developer.echonest.com/raw_tutorials/register.html
upload
Note that the path to the filename needs to be complete or relative to the working directory. Also, in this example there was no metadata identifying the title of the song. You may want to change this before uploading. Replace the API key with your key.
Use the analysis_url returned by the previous request. Note that it expires a few minutes after the request. But you can always re-run the audio_profile request to get a new analysis_url
