Re: [linux-audio-dev] Aeolus and OSC - comments requested

Steve Harris wrote:
> My preferred form would be something like
>
> /std_prefix/inst_name/base_freq f <base-frequecy>
> /std_prefix/inst_name/note_on iff <note-id> <octave> <velocity>
> /std_prefix/inst_name/note_off if <note-id> <velocity>

Hmm, what would the note-id be? And the octave is the log_2 of the
frequency, right?

Occam also seems to be a reasonable way for a 1-1 OSC-MIDI mapping,
thanks for the link. (But is that what we actually want in OSC?)

At least for modular synthesizers I'd guess that a standard way of
communicating notes would be a message to set the parameters of a synth
voice, something like this:

/set <voice> <gate> <freq> <gain>

<voice> would be the identifier of the voice to play, <gate> would be 1
to start playing the note (trigger the attack) and 0 to stop it (trigger
the release), <freq> would be the frequency in some convenient unit
(usually either Hz, octaves, semitones or cent) and <gain> the
amplification (velocity, if you prefer).

In many synths you would also be able to modify each of these parameters
(and probably some more) individually, while the note is already
playing. In the case of Aeolus the <freq> parameter could just be a MIDI
note number, as it cannot play arbitrary frequencies "on the fly".

The disadvantage of this fairly basic scheme is of course that the
client has to dispatch the voices himself.

Albert

-- 
Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr.Graef@email-addr-hidden-online.de, ag@email-addr-hidden-mainz.de
WWW:    http://www.musikwissenschaft.uni-mainz.de/~ag