Multi-language Max/MSP


This is perhaps an unusual article for Cycling ’74 to put on their web site, because it has to do with all the languages that Max/MSP isn’t. I have to confess that I’m not really a very good Max-user. I know only a handful of objects, and I am of the text-based generation that is still a little, um, “graphical-user-interface-challenged”. I basically use Max/MSP only as a window onto computer music languages that I am adept at using. More and more, though, I am also using Max as base platform for connecting these languages to each other. One of the really great decisions that the Cycling ’74 design team made was to make the development and integration of external objects relatively easy. This has been a real boost for the classes that I teach at Columbia University, and it has also allowed me much more creative freedom in my compositional work.

I had planned to present a paper/demo at the 2007 Spark Festival in Minneapolis, MN. However, snow. Icy precipitation. Two feet of this stuff was on the way. I rebooked my flight to return to the cozy warmth and safety of New York. I was bemoaning the fact that I would have to miss the paper session to Andrew Pask and Gregory Taylor at breakfast the day I was now leaving, and Andrew said (you have to imagine an early-morning Kiwi accent): “Hey mate, why don’t you write it all up for our web site?”

Before proceeding, download the Max 4.6 patches and information used in this article.

The Challenge

    [NOTE: The following text is written from a Mac OSX perspective, but the concepts should be equally applicable for Windows users. Obviously the externals I discuss will need to be installed to run the patches (a list of links is at the end of this article). A few of the externals I describe below aren't yet available for Windows, but soon!]

A lot of my work involves developing compositional algorithms using script-based languages such as RTcmix or ChucK. I also employ the timbral capabilities imbedded in these languages as well as languages like CSound, JSyn and SuperCollider. In addition to all this, I’ve come to appreciate the data structuring and control capabilities available through a conceptually-developed language such as JMSL or a higher-level “pure” computer language like Lisp. Finally, I have discovered the joys of connecting the audio flowing from all these snazzy environments together using applications such as Cycling’s own Soundflower/Soundflowerbed. I wondered, what would it be like if I set out to create a patch using all of these languages at once?

The Work

I decide to start my computer music language extravaganza with a randomly-shifting cluster of sawtooth waveform notes. Because I know RTcmix well, I choose the Max/MSP instantiation of the language, [rtcmix~] to create this effect. (See patch1-rtcmix.pat for this initial sawtooth foray)

patch1-rtcmix.pat

(By the way, this patch represents about 96% of my entire Max/MSP knowledge and capabilities…)

In this article, I won’t go into the details of how each of these languages work. There is a lot of on-line documentation for those interested in learning more. Plus with a little downloading you can hear for yourself how these demo patches function.

And hear them I do! Sawtooth waves get really annoying after awhile. Just ask my wife and kids. What to do with this annoyance? Filter it! There exist many many ways of using digital filters in Max/MSP, but some of the more interesting filters are included in the ChucK language, available in Max/MSP as the [chuck~] external. (See patch2-chuck.pat) I send the sound output of [rtcmix~] through a simple biquad filter in ChucK. The center frequency of the filter is controlled from the Max/MSP environment.

patch2-chuck.pat

This external filter control turns out to be a really good thing, because in a silly fit of western compositional conscience I decide that I need to set the filter center frequencies using Real LIve Musical Notation. For this, I can use JMSL. JSML is a java-based music notation and hierarchical scheduling language that has been ported to work in the [mxj] context. (See patch3-JMSL.pat)

patch3-JMSL.pat

JMSL has many capabilities, and I could have used it — or any of these languages for that matter — to control the performance evolution of the patch. Instead I’m using a [metro] object to cycle the JMSL note-sequence repeatedly and drive the [rtcmix~] and [chuck~] objects. Simplicity is my goal.

As fascinating as these nice, musically-filtered sawtooth sounds are, my personal aesthetic is begging me to add a decent droney bass sound. CSound to the rescue! It so happens that I had already built a CSound orchestra to make a droney bass sound. Including it in the growing patch is almost trivial using the [csound~] object, although a bit of additional work is needed to set the score up properly. (See patch4-csound.pat. The csdrone.csd csound score/orchestra file is included.)

patch4-csound.pat

The icing on the cake for this mash of languages is the inclusion of some high pitched pulse-width-modulation sounds using the SuperCollider (SC3) language. SC3 is different from the previous languages, in that it runs as a separate application ‘outside’ Max/MSP. By employing the Open Sound Control (OSC) protocol used by SC3 for triggering scripts and events, we can exercise coordinated control from within our Max/MSP patch. (See patch5-SC3.pat. You will also need sc3-pulseit.rtf SC3 script loaded into SC3, selected and interpreted properly to run the patch.)

patch5-SC3.pat

The big drawback to the relative ‘outside’-ness of the SC3 application is that the audio output is being sent to the computer DACs through a completely separate audio stream. What if I wanted to pipe the SC3 audio through a happy ChucK filter? There is a way to do this, but it does require configuration of the Cycling ’74 Soundflower application using the companion Soundflowerbed.app

What I need to do is set up Soundflower/Soundflowerbed to route the audio coming from SC3 into our Max/MSP patch. There are two ways to do this, and I’m going to describe the “default” way. SC3 normally writes audio to the plain-old two channel output of the computer. We will use Soundflower/Soundflowerbed to reroute this output into Max/MSP and choose one of the other Soundflower outputs to audition the audio from our ever-growing Max/MSP patch. Here’s how:

  1. Start up the Soundflowerbed application. We are going to select two of the 16 channels to be our “audio monitoring” output. Just so we can remember easily, let’s use the last two (channels 15 and 16) to do this.

    From the Soundflowerbed drop-down menu under the Soundflower (16 ch) listing, be sure that channels 1-14 have None checked for their routing:

    Set the routing for channels 15 and 16 to Built-in Audio [1] and Built-in Audio [2]:

  2. Next we want to set the default system audio output to go to Soundflower. Select the Audio Setup… menu item from Soundflowerbed. This will bring up the “Audio MIDI Setup” Preference. Set the Default Output to Soundflower (16 ch):

    [NOTE: Be careful -- once you set the "Audio MIDI Setup" default to Soundflower (16 ch), it will affect other applications. You will probably want to reset this to Built-in Audio when you are finished.]

  3. Now start the patch6-soundflower Max/MSP patch, and use the DSP Status… window (under the Options menu) to set the Driver and the Input Device to Soundflower (16ch):

    At this point, audio output from or original patch is disabled, or at least not able to be heard.

  4. To route the audio so that it can be heard, and to route the default output of SC3 into our patch, I need to change the patch so that I can send audio on [dac~] outputs 15 and 16 (the “monitored” outputs) and bring the SC3 audio into the patch from [adc~] inputs 1 and 2 (the default SC3 channels). This is easy to do by specifying what channels I want in the [dac~] and [adc~] objects. (See patch6-soundflower.pat)

    patch6-soundflower.pat
  5. At this point, start up SC3, read the script, fire up the Max/MSP patch, and sound!

    There are two points I should make about the SC3 routing. The first is that SC3 is smart enough to take advantage of all the Soundflower inputs and outputs. It is not necessary to use the default. The SC3 output ugens can be used to write to any of the Soundflower channels directly.

    The second point is slightly more subtle, but it hints at an extraordinary world of possibility. The output of any audio program can be routed into Max/MSP using Soundflower. In performance, I have used the marvelous SPEAR analysis/resynthesis program as a performance interface to “scrub” sound analyses and process the resulting sound. Similarly, the output of the Max/MSP patch itself can be sent elsewhere, perhaps directly to a program like Digital Performer for recording or additional processing. The only drawback is that any program without the ability to address all the Soundflower channels (like SC3) will only be able to write to the default channels 1 and 2. The combination of several ‘external’ applications may wind up being mixed inadvertently.

    Now SC3 audio is flowing through the patch! Yay! I can filter it, I can mangle or munge it, I can mix it willy-nilly with the rest of my sounds. But instead I’m going to make one final addition to the patch, using a more general computer language.

    As happy as I have been with the [metro] controlling the triggers of the different languages in the patch, I would much prefer to use a fractal technique to determine starting points for triggers. I’m just that kind of guy. Is it possible to do this by concocting some bizarre dataflow combination of [metro] [uzi], [if], or other esoteric set of ‘standard’ Max/MSP objects? Perhaps, but it would take someone with a brain radically different than my own to make it happen. Instead, I’m going to turn to the ur-recursive language Lisp to do the work in a few simple lines of code. The [maxlisp] object lets me do this. (See patch7-maxlisp.pat, the lisp code is in the file fract.lisp)

    patch7-maxlisp.pat

    My work is done! Five separate computer-music languages, one general-purpose (and also separate) language, all mished together via Max/MSP into one cooperating mass of sound! And I haven’t even hinted at the thrills to be had by employing powerful but more Max/MSP-friendly externals like Peter Castine’s Litter package or Peter Elsea’s Lobjects. And java! And javascript! Yikes!

    The Final Observations

    I’d like to make two final comments. The first is a plea to developers, and the second is a goad to Max/MSP users. For developers: think shared libraries and loadable bundles! The Soundflower routing for SC3 above works, but I would much prefer to access SC3 functionality directly from within Max/MSP. Or (for that matter) I wouldn’t mind being able to access all of Max/MSP within SC3. The basic idea is that I like the tight-coupling that can be gained through the imbedding of one application directly inside another. I’ve used network approaches in other instances in the past, and although they work well for most situations, the ability to integrate control very closely can lead to much better standalone interfaces and applications. I would love to see the day when bringing in an external application is a simple matter of bundling it properly, finding the right entry-points, and then using the application completely inside an alternative development environment.

    The prod to Max/MSP users: I have to bite my e-mailing tongue on the Max/MSP mailing lists when I read people struggling to work with the creation and accessing of something as simple as indexed arrays of values. A small investment in learning something like javascript or an even a simpler language like RTcmix or ChucK with rudimentary data-structuring capabilities would solve many of these problems in one or two lines of code. Yes, lines of code. There are some things that a dataflow approach just isn’t all that good at doing (read your Knuth). Why not take advantage of all the tools available?

    And available they are! Most everything I’ve used above is downloadable for free or for a very modest sum, and there are many more packages ready for the asking/using. As an educator intent on teaching a wide range of approaches — I believe that different languages do in fact structure our creative thinking differently (but that’s a whole ‘nother article) — the ability of Max/MSP to “glue” them all together is a real boon. More importantly, the extended capabilities to which I know have access makes composing and creating music downright enjoyable again. All those sounds!

    If you are interested, the original SPARK paper that I did not present because of my snow-fear is here. But you’ve pretty much read it already.

    - Brad Garton
    Professor of Music
    Director, Columbia University Computer Music Center

    http://music.columbia.edu/~brad

    Here is an alphabetical listing of many of the objects and languages discussed above: