Polyphony on a single key.....why not?

[Wiggum]

Hey all,

 

There are no hardware synths that I am aware of that allow you to play muliple notes on the same key (without cancelling the previous note you played). A prime example would be a cymbal sample. If you repeatedly press the key, each new note cancels the decay of the previous note. The result sounds artificial at best.

 

I never realized this until I got Steinberg's LM4 virtual drum machine. This instrument plays each drum hit until the end, regardless of multiple hits. It makes the drums sound incredible (particularly the 24 bit Wizoo kits).

 

This is not just a valuable feature for drums, but I could see applications for piano and stringed instrument samples. When I play a bass guitar patch, I can't emulate continual picking. I can hold the sustain pedal, but I still only get the decay of one note.

 

Why don't synth manufacturers extend polyphony to individual notes? The sound engines are certainly capable of it, and I can't find a good reason against it. The potential for phase cancellation crossed my mind, but with the endless modulation possibilities on modern synths, each note tends to have it's own character anyway. And if you chose not to use it, why not implement a software switch?

 

Any thoughts?

 

Wiggum

 

 

This message has been edited by Wiggum on 03-25-2001 at 01:04 AM

[murph]

Actually, many keyboards will allow for what you're talking about. For example, take a Kurzweil, put in a sampled drum loop, hold the sus pedal down, play middle C, play another middle C and you'll hear two drum loops. Multiple notes, same key. It's not rocket surgery.

[Steve44]

Here's a rather lengthy post on this issue, but first I have to say to murph: it's not rocket surgery <-- LOL! combination of rocket science and brain surgery = cool.

 

So anyway, on many synths this parameter is only available in drum mode, and is there not only for cymbal crashes but also snare rolls and triangles. On the other hand, there are also monophonic groups for doing hi-hats correctly. For instrument sounds it's often difficult for the sound engine to produce two versions of the same thing, especially if it's straight sample playback. I remember the Korg O1/W couldn't really play two of the same note at the same time even if they were on different midi channels (but the same patch). But most modern synths do it pretty easily.

 

But besides this, there is a difference in a way a note should react on each consecutive strike. This applies best to acoustic guitar, where restriking a note can make the note grow and change in timbre, which isn't the same as overlapping samples would sound in a keyboard. There's a cool demo of this effect on the Korg Oasys[/url page which works there because they have a "Poly-restrike" parameter built into the physically modeled guitar.

 

On analog and virtual analog style synths, once you restrike the note, the previous note goes into the release stage, but is still being heard without a problem, which can cause some interesting things provided you have a flexible release stage (as on the Andromeda).

 

 

On the complete opposite end of this subject there is idea of multi-timbral polyphony which was brought up in the article on TONTO in this month's Keyboard. The idea is that playing multiple notes of the same sound shouldn't reproduce the same sample, but should change in timbre slightly because in a real orchestra it would be played by a different player (holding a separate instrument by a different manufacturer), not just a different note. This goes beyond even keyboard tracking which itself isn't used as much as it should be nowadays - some synth programmers forget that real instruments have registers. (I find it especially irritating when a modern synth doesn't have breakpoint key parameters or slopes for the tracking amount, although Andromeda does address that.) But this idea instead would have each separate note as a different character of the same instrument, such as the silver trumpet played by the smallish guy and the gold trumpet played by the chubby guy. Of course it's all analog, but it does require sophisticated keyboard scanners that are able to track individual lines without hard-set split points. This "floating zone" feature is something I wish would've come into the mainstream synths long ago.. as far as I can tell the only things that have ever had it was a Buchla instrument called Touche and the Oberheim Perf/X Controller, the Cyclone I think.

[marino]

On the Oberheim Matrix-12, God bless whoever designed it, I can program a Multi with a keybord assign mode called "Rotate". This will assign every consecutive key strike to any number of different patches in series, up to 12. They can be, of course, slightly different versions of the same sound, or wildly different sounds. Or the same sound, but with a different tuning. Etc.... http://www.musicplayer.com/ubb/smile.gif

 

marino

[d-kay]

cool idea with the rotate-stuff. I've got Reaktor and I'm confident that I can program the damn thing to play a different timbre for each new-pressed note (when there is one or more already pressed down) thus creating cool "vocal" choir stuff, but Analog!. Imagine a singer with a backup choir filling in with different kind of voices!. The easiest way would be to offset the filter just a little bit for each incoming note.