Re: Genetics (Analog to Midi) and Re: Music Box Designs and Re: Me and the Convention
By Larry Smith
This was originally send Oct 13th, but it bounced the week I was gone. Here it is again. I will be following up on this once I have caught up my mail.
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To: rolls@foxtail.com (Automatic Music Mailing List)
Date: Fri, 13 Oct 95 14:15:32 -0400
From: larrys@zk3.dec.com
Subject: Re: Genetics (Analog to Midi)
Karl_Petersen@smtp.scpboi.com:
re: genetics
> The next question is, what hardware and software are necessary to give
> this a trial run? I have lots of overnight time available on DOS and
> UNIX workstations at home, and have my own resident AIX administrator
> and C-writer, but he has not osmosed the genetic algorithm recommended
> reading list.
>
> Ok, Larry, Tag, you're It =).
The most important software task is to design the comparator, because that is what will define how well the algorithm will work. That will probably merit a discussion about what and how to measure success.
Beyond that, you need a way to suck up a target performance as a .wav file, and a way to create a .wav file from a midi performance short of just playing the thing out loud and digitizing the result - that would work, but it would be mighty annoying to listen to while it worked, I'm here to tell you. Other than that, you need just a basic genetic algor- ithm, a number of them have been published in various computer rags and I expect a short conversation with a gopher, or perhaps a web search, will quickly turn up some archives with C++ code implementing a reason- able algorithm. Almost any hardware will suffice, but faster is obviously preferred. If you need a sound card to do these conversions a Pentium would be a logical choice.
The comparator will also implement your contraints - restricting target voices, for instance. The algorithm will be faster and more accurate if the output voices are similar to the input voices - which is why I came up with the idea, I should be able to use it to take recordings of musical boxes and turn them into midi fairly easily. But taking something like, say, "In a Gadda Da Vida" with output set to a music box voice may lead to something a bit...er...funky. Some other constaints we'd like would control the number and timing of notes - the algorithm will call for 86 notes at prime-number picosecond intervals if that will better mimic the target .wav - and while that may be fine with the midi-to-.wav simulator, it would be hellish to try to pin, dontcha know. To do a straight whatever-to-midi will be easier and harder - easier because the voices will match, harder because the algorithm won't care if some- thing is hard to play provided it sounds right. Some "post output" scanning might be called for that would do things like scanning a bar of 60% violin notes and replacing the odd cello note with the equivalent violin notes.
Subject: Music box designs
I was looking at tremolo boxes the other day - these are (I think) the ones with duplicate notes in the comb in order to achieve a sort of sustain. I was wondering if anyone had thought of using spinning disks to "bow" comb teeth to accomplish this, it would seem a fairly logical progression from classical music boxes and might make for a really lovely sound, sort of like a cross between a reed organ and a music box.
Subject: Me and the Convention
Well, I'm off to soggy Florida for a week at Walt Disney World. I might still drop by the public mart at the convention even though Nancy Latti cleaned me out of my total acquisition budget for the next two years, so I might see some of you folk. I should have plenty of mailspace on this node, so keep the digests coming, and I'll see you folks Monday, the 23rd. Looking forward to hearing everyone's take on the convention. If anyone here goes to Charles Hind's workshop on building new musical boxes, _please_ collect whatever material you can and post a full review of what he's been working on!
regards,
Larry
[ Larry,
[ Its too bad this last part didn't get here in time. Did you talk
[ to any of our subscribers while you were at the convetion ?
[ Jody |
(Message sent Mon 23 Oct 1995, 13:36:06 GMT, from time zone GMT-0400.) |
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