linuxaudio.org

Jeff McClintock wrote:

quoted text
>> From: David Olofson

>>

>

>

>> These issues seem orthogonal to me. Addressing individual notes is just a

>> matter of providing some more information. You could think of it as MIDI

>> using

>> note pitch as an "implicit" note/voice ID. NoteOff uses pitch to "address"

>> notes - and so does Poly Pressure, BTW!

>>

>

> Not exactly note-pitch. That's a common simplification/myth.

>  MIDI uses 'key-number'. E.g. key number 12 is *usually* tuned to C0, but is

> easily re-tuned to C1, two keys can be tuned to the same pitch yet still be

> addressed independently.

>  It's a common shortcut to say MIDI-key-number 'is the pitch', it's actually

> an index into a table of pitches. Synths can switch that tuning table to

> handle other scales.

>

> A MIDI note-on causes a synth to allocate a physical voice. That physical

> voice is temporarily mapped to that MIDI-key-number so that subsequent note

> control is directed to that voice. The mapping is temporary. Once the note

> is done the mapping is erased. Playing the same key later will likely

> allocate a different physical voice.

>  The MIDI-key-number is therefore an 'ID' mapping a control-source to a

> physical-voice.

>

>

>> Anyway, what I do in that aforementioned prototyping thing is pretty much

>> what

>> was once discussed for the XAP plugin API; I'm using explicit "virtual

>> voice

>> IDs", rather than (ab)using pitch or some other control values to keep

>> track of notes.

>>

>

> I agree that addressing notes unambiguously regardless of pitch (or any

> other arbitrary property) is the ideal. I wish more sequencers were not

> locked into a narrow 'western pop music' mode of operation.

>   But many MIDI alternatives have been proposed without looking deeply

> enough to realise that MIDI already supports very flexible note control.

>

> MIDI's significant flaw is it's grossly outdated 7-bit resolution, the

> underlying voice model is sound.

>

>

>> Virtual voices are used by the "sender" to define and

>> address contexts, whereas the actual management of physical voices is done

>> on the receiving end.

>>

>

> You have re-invented MIDI with different nomenclature ;-).

>

> Best Regards,

> Jeff McClintock

Indeed, even low cost sound modules support different tempered scales. A

good example for the mapping are percussion modules. For percussion it's

more common to have non-western tempered scales.

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