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At 8:33 AM -0800 1/2/03, S V G wrote: >From there it is up to the pitch to MIDI converter to unravel all >this information...if you play a note within 50 cents (half a >semitone) >either side of middle C with a fretless guitar, the pitch to MIDI >device will output the note "C" plus the appropriate pitch bend >information (or not). Another note played within 50 cents either >side of C# will trigger a new note as "C#". The only time this >doesn't hold true is when you pluck a note and then slide your >finger up or down the string. The note has already been >activated and chosen and then the pitch bend information is sent to >modify that note up or down an octave or more. RZ: This system has both advantages and disadvantages. It assumes that pitch bends will always start within a semitone of the nominal pitch, but it's quite common for some players to bend down from a whole tone or a minor third above. SVG: This shouldn't be too big of a difference to matter. RZ: The system I mention as being available on the Peavey Cyberbass (each string outputs a single MIDI note plus pitch bend within a two octave range)... SVG: This doesn't jive with my understanding of how MIDI works, one note that gets bent up or down an octave? Wouldn't that sound weird at the extremes? RZ: ...has some interesting possibilities for fretless and even fretted MIDI guitars. For instance, it allows playing with flexible intonation. Microtonal players (whose pitch discrimination can be uncanny) would be able to play guitar synth in Just or other intonations without the synth having microtonal features. Even though many synths have tuning capabilities, it requires switching presets in order to change from one to another. With a MIDI pitch bend based system the intonation would be left entirely to the player. SVG: Again, I'm not sure that I understand what you are referring to here. I've been building microtonal instruments for the past 25 years, though my knowledge of how MIDI works is on the scant side. If a patch had a pitch bend resolution of +/- 1 semitones, wouldn't this be enough to obtain most any microtonal interval as long as you don't bend the note outside of that semitone range? And the pitch bend accuracy would be to the nearest 1.5625 cents (100 cents divided by 64) which is close enough for rock 'n' roll (though some would moan in a most pitiful way). RZ: There are certain technical issues related to pitch bend resolution. Unfortunately most MIDI equipment seems to be designed with 7-bit pitch bend and this permits only 128 discrete values. This means that bends are limited to 63 or 64 steps up OR down. With a semitone bend the individual steps are about 1.5 cents; a while tone is about 3.1 cents. Both are OK, but if you stretch 128 values over a two octave range you get pitch increments of nearly 19 cents! SVG: Okay, I tried this on my keyboard synth and I found out what you're talking about. If I set my pitchbend range to +/- 12 semitones, my pitchwheel gives me a "stepped" output as opposed to a smooth slide. I must have been getting around a 10 cent jump with each increment. RZ: The technical solution to this is to use the full two-byte, 14-bit resolution allowed by MIDI, resulting in 16,384 steps and pitch resolution of about 0.15 cents. I don't think there are many sound modules that can match that. The Cyberbass Voice Module and the Oberheim Matrix synths can handle it. SVG: My Emu synths all have a resolution of +/- 64 per semitone which is 1.5625 cents. Not great but better than nothing. Kurzweil has a resolution of +/- 100 per semitone which is in 1 cent increments which is a whole lot easier for a musician to work with (one of the rare moments when Kurzweil had the musician rather than the nerd in mind...) and other systems tend to follow one of these two models. However, these numbers are referring to the gradations available when constructing microtonal scales as well as the pitchbend range. With the Kurzweil, you set up one octave and all the octaves are locked into that same tuning. With Emu, you have to set the tuning for every single note which is more labor intensive yet it offers much more flexibility (i.e. octaves don't have to be in tune with each other, which is essential for most ethnomusicological scales). Regardless of whether you are using a fretless or a fretted guitar, you can set a user definable scale on your synth, turn off the pitchbend, and anything you play on your guitar will ipso facto sound within that scale that you defined. It would be imperative to not blend the acoustic sound of the guitar with the synth sound if that were the case. Still it holds some potential. RZ: BTW - Middle C is "C4" no matter what Yamaha says. SVG: I know that MIDI was developed with several musicians on the consulting panel. What were they thinking? That they could just ignore the modern acoustic usage? Especially since there seems to be no overwhelming reason that they couldn't just keep C4 as C4. >I can personally vouch for the Godin/RMC combination, the sound of >my nylon Multiac is extremely satisfying to my ears as a classical >guitarist. RZ: Any comments on the difference between Multiac and ACS-SA? SVG: I actually owned the ACS-SA for a few weeks by accident before obtaining my Multiac-SA. The ACS is a less expensive guitar, being mostly a solid body nylon stringed instrument made out of western maple. Ergonomically, it was too heavy for me and it didn't hang on my body well. Though I don't play electric guitar and it was probably not too unlike its close cousins. My sense is that it tracked slightly better than the Multiac as far as my GR-33 was concerned, probably due to fewer acoustic resonances getting in the way. It also had a little better sustain. As for the Multiac, it is much lighter, still hangs a bit awkwardly on my body (I think I'd do better with the Godin Concert Classical as the body joins the neck at the 12th fret rather than the 15th fret) and it has a far superior sound straight off the piezos. Acoustically it is much louder than the ACS which is a drawback if you are using a VG processor with alternate tunings, yet a plus in most other areas. It it made with a spruce soundboard and a nice sized chamber in the center portion. If I was going mostly for the synth access qualities, I'd get the ACS. With it I found that I could get more expressiveness both in tracking, sustain, and amplitude characteristics using the onboard synth of the GR-33. If I was interested in the acoustic qualities of a nylon string guitar blended with synth access, I'd go for the Multiac. Since I find myself blending the two sounds a lot, I'm a happy camper with my Multiac. SVG __________________________________________________ Do you Yahoo!? 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