EMUSIC-L Digest Volume 37, Issue 04 This issue's topics: Composition Project Convolution filter project:3 (?) (2 messages) MAX Performance Substrate - some comments Sound waves (2 messages) Thirst for knowledge Your EMUSIC-L Digest moderator is Joe McMahon . You may subscribe to EMUSIC-L by sending mail to listserv@american.edu with the line "SUB EMUSIC-L your name" as the text. The EMUSIC-L archive is a service of SunSite (sunsite.unc.edu) at the University of North Carolina. ------------------------------------------------------------------------ Date: Wed, 5 Feb 1992 15:08:44 -0800 From: Darren Gibbs Subject: Composition Project Greetings! I am hoping to find volunteers to participate in a piece I am working on for my upcoming MFA thesis concert. The only technical requirement is some kind of portable recording equipment. The rest is up to your imagination, the more creative and divergent the better... The inspiration: The character of a space is determined, to a large degree, by the patterns of events which keep on happening there. - Christopher Alexander The instructions: Visit a local environment which somehow possesses an especially unique, profound, or vibrant quality (positive or negative). Attempt to capture and/or illuminate the character of this space with a pattern of sound(s) recorded there, indigenous or introduced. I plan to collect the material from these "field" recordings for use in several possible ways. i.e. What I do next depends on what kind of stuff I get back. If you can send soundfiles by anonymous FTP that would be fantastic. NeXT .snd is optimal but 16-bit, 44K, mono or stereo: AIFF, Sound Designer II, IRCAM, or Sun .au is OK. Please include a text file containing who you are, the format of your soundfile(s), and if you like, an outline of what you did. anonymous FTP: vax.mills.edu (144.91.1.5) use the directory: submissions/darrens.project If you send media (DAT or cassette) I promise to return it immediately plus incoming postage. Don't forget to include format info with cassettes- no DBX please. I'd like to start on the next phase of the piece by the first week of march, so anything I receive after that may or may not get used. Hopefully this leaves enough time for folks to do some interesting stuff. Please let me know if you're interested or have questions. thanks, Darren Gibbs Center for Contemporary Music Mills College Oakland CA darren@mills.edu 510-531-3523 P.O.Box 9343 Oakland CA 94613 ------------------------------ Date: Tue, 4 Feb 1992 10:35:38 -0800 From: Darren Gibbs Subject: Convolution Greetings Have any of you ported convolvesf from the CARL software synth package to the NeXT, or know of anyone who has? darren gibbs center for contemporary music mills college oakland ca ------------------------------ Date: Tue, 25 Feb 1992 12:15:55 EST From: ronin Subject: filter project:3 (?) gawd, science is tuff... we still don't have a complete data set on the juno's lopass, cuz we keep running into various weirdosities, but we have come up with one interesting preliminary result: the juno's lopass is an active gain device. it not only attentuates frequencies below its cutoff, but significantly *amplifies* frequencies *above* its cutoff. the result of this is a greater ratio between points on its characteristic curve... in other words, it's quite a bit sharper on its rolloff. nice trick. what we're doing at this stage, by the way, is taking two 'perpendicular' data sets: one with a fixed test tone and a sewpt filter; and one with a fixed filter position and a swept test tone. we'll then drop these data sets into mathematica and interpolate an input frequency/filter cutoff/db(in/out) surface plot. then we'll take a line of 'generated' (as opposed to 'experimental') data off the plot, and then do an experiment to show proof of method. i would like to show that the two original data sets are the only ones necessary to correctly characterize the entire filter. we'll see. as for other filters, we've decided to order CEM chip directly from paia, and test it on a board. i don't feel like waving probes around the inside of my prophet any more than i have to, and you may remember the debacle with the matrix 6... the damn thing uses a later, more integerated CEM chip on which the filter is not isolatable. onward. -----------< Cognitive Dissonance is a 20th Century Art Form >----------- Eric Harnden (Ronin) or The American University Physics Dept. 4400 Mass. Ave. NW, Washington, DC, 20016-8058 (202) 885-2748 ---------------------< Join the Cognitive Dissidents >------------------- ------------------------------ Date: Fri, 28 Feb 1992 11:08:20 +0000 From: Nick Rothwell Subject: Re: filter project:3 (?) Vaguely related topic here: on the MicroWave, I notice that if the cutoff frequency is above or near the top of the audible range, then increasing the resonance causes the low frequencies to drop, so resonance causes the filter to act like a broad bandpass. Is this a quality of the filter or of the raw wave data that's going into it? I've never seen (heard) lowpass analogue filters do this before (except on the PPG), although it's very nice. Nick. ------------------------------ Date: Mon, 24 Feb 1992 17:42:15 GMT From: nick@DCS.EDINBURGH.AC.UK Subject: MAX Performance Substrate - some comments [If you're reading this more than once - sorry. I'm posting it to a few places since there's been some interest in it already. Besides, I reckoned it was about time someone raised the S/N ratio in comp.music. ] Some background: playing a MIDI rig live is a hassle. Preparing material for live use is also a hassle. Even sequencing material in the studio is a hassle. Once you get to a certain number of MIDI devices (in some cases, one), you encounter all sorts of race conditions due to the way the devices handle setup messages, patch changes, and controllers. Some examples: the D-550 can receive on two channels, but takes program changes on one of them, so you'd better not be playing the other one at the same time. The MKS-70 can accept program changes on its patch channel, but that blows away any voices on the tone channels, and when you reset the tone programs the volumes are all screwed (i.e. reset to the tone VCA output levels). The Wavestation can take switching messages for its multisets (these are SysEx only, which is, yes you guessed it, a hassle) but this loses the patch assignments for the performances being played, and in some FX configurations, kills all the notes as well. The D-70 kills all sounding notes on all 6 receiving channels when you switch a performance, and even when you select a different keyboard part. The MicroWave sustains voices over changes, but a switch of multiset will lose patch assignments, and the output stages glitch from time to time as well. Let's think of this in terms of master keyboards. I just read an article by Julian Colbeck, where he explained what a fantastic idea a master keyboard is, because with one push of a button you can reconfigure your entire keyboard rig. Great, except that this is exactly the functionality I don't want - fine for 3-minute pop songs but useless for longer pieces. I posted another article about this recently: the whole Stop'n'Go mentality (play a song, stop, reconfigure, play another song) permeates the design of, and use of, all our instruments, rendering most keyboard synthesisers and master keyboards totally useless for serious live work (and I still want to know why none of the keyboard magazines have noticed yet). Let's think in terms of studio sequencing for a second: For a recent project, I spent a week or so putting the sequences together. The worst of this was tracking down and fixing race conditions: manual controller chasing, if you like. Read the paragraph above and then think about inserting, tediously by hand, all the controller messages for several sequence chunks which are playing at the same time, such that nothing cuts off anything else, and all the volume levels and so on chase properly. Hmm, can this new track play device Wavestation/6? Sure, except that, damn, I'm about to flip multiset to get the vocoder, so I have to delay that intro, which means moving the sequence chunk back one bar, but I can't do that because it flips an MKS-70 tone, which will screw up the volume of the tone with the long decay running through the LXP-5, so I'll have to shift the LXP-5 balance control messages, except that... You get the picture. I can spend days doing this kind of thing. And I hate it. I'd rather play. Talking of playing: OK then, playing live. It takes many days to program up the keyboards so that they'll only send patch changes when the destination voices are idle, without dropping other voices. Think of that in a live situation, with short time windows to reconfigure the devices while other stuff is sounding (and while you're playing). Too early or late, and you overrun a patch change from the sequencer and you're screwed unless you've programmed up some recovery actions. So, zere ve haf der problem, yes? Let's go back to Colbeck's comment: one button press, reconfigure everything. No. What we want is the following: one button press, *CUE* change messages to be sent to devices *when it's safe to do so*. That's point one. Point two is that we want to chase controllers (such as volume). Point three: we want to treat all reception instruments as independent from the point of view of patch changes, so that (for example) sending a patch change to reconfigure the Wavestation's multiset leaves all the other channels (the reception performances) intact. Conventional sequencers are useless for this kind of work. (In fact, I'm starting to feel that conventional sequencers are incredibly stifling things to use live, and really dislike doing so - but that's another thread.) However, MAX is ideal for this kind of thing. I spent the weekend working on something, and I have the basic functionality in place and working. An important observation is that all this is *not* a function of the controller keyboard, but of a control substrate attached to it. Given that, all that a controlling keyboard has to do is provide zones, transposition, patch changes in a naive manner, and get its notes and controllers matching across configuration changes. Ideal world scenario: all devices (i) can sustain notes on any reception channel, regardless of patch changes on that channel, and (ii) no reconfiguration or change can lose patch assignments on any other channel. This is the functionality we're heading for. Of course, many machines are too stupid to hold notes through program changes, so we have to to the opposite: delay patch change messages until all voices have stopped sounding. This is the MAX code I have working so far (together with the other basics of the substrate, which interface to OMS and allow me to configure source and destination instruments as virtual sources and destinations which are independent of changes to the OMS configuration (indirection is essential here), and provide patch change mapping tables). The tricky thing was to chase notes and sustain pedal properly. Patch changes must be deferred until no notes are gated and sustain is off. What makes it *really* tricky is that note decays must be handled properly. Waiting for all notes to lift isn't good enough, since the notes may decay, so there's some timing involved. Again, MAX is ideal for this functionality. Integral to the patch mapping table is information about decay times for the named patches. The substrate takes this information onboard. (This is rather a naive approach: some patches have no sustain, and the release and decay envelope stages might be wildly different. However, I decided that I wanted an algorithm which didn't require every note to be tracked individually, so that knocks out anything too clever. At present I have two modes: NO_SUST and SUSTAIN, to deal with patches which have no sustain portion, but it's messy - about 30 square inches of MAX at least - and I'll probably rip it out.) This is the current state of things. I'm building a matrix of instrument drivers, each of which tracks notes and controllers in this way (and has LED status indication for the various gates - cool), and then I'll impose a parent/child heirarchy on them so that some instruments get "reasserted" if the parent patch (multiset, whatever) is changed, and also so that parent changes are deferred until all children are idle. This requires some delicate programming: I'm using a sort-of remote procedure call protocol at present to achieve things like this. Once done, I'll build the master keyboard part of this and plug it into the substrate, and then start slotting in performance modules (such as the event sequencer) between keyboard and substrate. Here's an interesting idea which just occurred to me: I can build looped sequence patterns and the like which contain program changes and complete multiset changes if I want to - the substrate will know when it's safe to switch things and keep track of everything. What's really good about this project from my point of view is that (i) it'll make live performance so much nicer, and (ii) it'll make working with musical ideas so much quicker - just point and press, and the devices will work properly, rather than hacking around with low-level stuff on screen in a conventional sequencer. And, importantly, this isn't some huge months-of-work software project which takes me out of music making for that time. All of the above has come from working with MAX for under a week. Given that, I'm very impressed with the package indeed. I think that's all for now. More later, when I have something more to report. Nick. ------------------------------ Date: Mon, 24 Feb 1992 20:35:20 EDT From: Marcelo Todaro Subject: Sound waves Hi everybody. I am new on this list and I am looking for people who research artificial reproduction of natural sounds. I have a tesis to do it by recording the sound of, for example, a violin, analising the form of its waves and trying to create a "clone" of it based on that wave form. I think it's more difficult than try to create an organic skin using sintetic materials. Who can tell me something about it? Thanks for time and sorry for bad English. Marcelo ------------------------------ Date: Tue, 25 Feb 1992 11:08:00 EDT From: RAY BROHINSKY Subject: Re: Sound waves >recording the sound...and trying to create a "clone" of it based on >that wave form. Lots of work has been done on this. If your local music/technology library has back issues of the Computer Music Journal (back to the second year, at least) there are a number of articles there that may help. Included in these are analyses of acoustic instrument notes to something like the 27th partial, showing both amplitude and frequency deviation. (Work of J. Risset) >more difficult than try to create an organic skin using sintetic materials. Is this your other choice for thesis? 8^) Lots of published work on analysis and synthesis of acoustic-like sound exists in the various acoustic journals. A visit to the periodical guide (if it's available) in your local library might help a lot. Likewise, perusing back issues of Acoustica, the Journal of the Acoustical Society of America, and even Catgut (a journal of another society which I can't remember the name of, and which is responsible for the `Violin family' of instruments, OH, that's it: the Catgut Acustical Society of America. The maker of the Violin family was Carleen Hutchens.) I'm sure someone on Emusic-L will flesh out this bare skeleton. As for your `bad English', you do as well as some who live here! ;-) raybro ------------------------------ Date: Sat, 15 Feb 1992 23:11:11 GMT From: Thunder-Thumbs Subject: Thirst for knowledge Hello, everyone. I am a complete novice at a lot of this - I need a friendly e-mail mentor to show me some of the ropes. I'm trying to put together a good computer system for the purpose of all the good multi-media stuff, mostly music. I decided to get the IBM instead of the Mac, because I am an engineering student, and will need it for other applications. Here is what I have so far: IBM 486/33, 80M, 4Mram, SVGA monitor, 64K cache, Dot Matrix Printer Finale version 2.0.1 Analog 4-track (Vestifier) I have been trying to research about what Midi stuff I need to buy for my IBM, but I've only heard about game cards, and I'm not interested in playing games. In the next few months, I may also get a full size electric piano (I want a Kurzweil, but may have to settle for a Clavinova), for speedy note entry on Finale. I also want to do recording, though, and write some C programs for computer music. Can anyone recommend ANY course of action for me? I'm looking for a recording program comparable (or better) to Performer for the Mac. Basically what I need is some good Midi advice (what to buy), software advice (what to get), and research advice (where to look). Anything else informative would be nice too. For instance, does anyone know the status of writeable CD drives?... Textbook recommendations? Where can I get the Finale upgrade? I've registered, but haven't gotten anything back. PLEASE, fill my mailbox... -- * Curt Siffert * 'In the heart of the rain forest, it * * Thunder-Thumbs * was doing what it usually does in * * siffert@ucsu.colorado.EDU * rain forests; which is rain; hence * * (What's an opinion?) * the name.' - Douglas Adams * ------------------------------ End of the EMUSIC-L Digest ******************************