11 Feb
2010
11 Feb
'10
5:38 a.m.
On Sun, Feb 07, 2010 at 08:03:36PM +0100, Lorenzo wrote:
This translation requires a bit of explanation. The first set of characters
("cdefgabCDEFGAB") are two octaves, the lower one represented by the
symbols "cdefgab" and the upper one by the symbols "CDEFGAB". The two
sets
are note names used in the tune, declared at the top:
tune="C 4, E 4, D 4, g 2, C 4, D 4, E 4, C 2, \
E 4, C 4, D 4, g 2, g 4, D 4, E 4, C 2,"
But the MIDI devices expect MIDI note numbers instead of symbolic names, so a
translation is needed. The symbol "c" is translated into the character
"<"
(character code 0x3C, decimal 60), and the symbol "C" into the character
"H"
(code 0x48, decimal 72). The character codes are the MIDI note numbers, and
we are writting them to character devices (/dev/midi*).
The MIDI note numbers and their corresponding musical notes can be seen in
this nice graphic:
http://en.wikipedia.org/wiki/File:NoteNamesFrequenciesAndMidiNumbers.svg
If you don't need to deal with note names, I suggest you to use the MIDI note
numbers directly. This gives you the widest possible range of notes.
Another completely different approach might be to create a Pd patch with
all the 'random midi logic' and then call it from bash with the -nogui
option... But not sure if this would fit in your scenario...
I used this little script Thursday night to drop some random samples in during stops in a
song. First time I've busted out tapeutape live too. It went over pretty well.
Two sets of samples, triggered by two different pads on the Novation.
-ken
---------------
#!/usr/bin/python
import os,sys
import random
import alsaseq
import alsamidi
sys.path.append('/home/music-projects/lib')
import alsaevent
alsaseq.client('randomsamples', 1, 1, False)
def main_loop():
while True:
msg=alsaseq.input()
if msg:
ev=alsaevent.AlsaEv(*msg)
if ev.type == alsaseq.SND_SEQ_EVENT_NOTEON:
if ev.notenum == 36:
alsaseq.output(alsamidi.noteonevent(0, random.randint(0,24), ev.vel))
elif ev.notenum == 38:
alsaseq.output(alsamidi.noteonevent(0, 30+random.randint(0,28),
ev.vel))
#### MAIN
if __name__ == '__main__':
main_loop()
> The note to be sent should be specifiable on
command line, along with
> length/velocity ... probably would be enough.
>
> Any ideas?
>
As an example, here is a bash script that can be used with cron, to play
hourly a tune and some strokes.
Thanks Pedro, that's quite useful.
I'm using the playnote function from your script. I see you make a
translation of note names to other ascii chars using tr (before you call
playnote), and it's this latter "scale" string I'm interested in, as
my script does not need to deal with note names at this stage.
I've used an expansion of the string "<>@ACEGHJLMOQS" to
"<>@ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" which does
give me a wider range of notes, but is very
middly, there's no bass
notes nor anything from the high octaves.
How might I get the bass and high end?
Another example is attached. In this case, the script plays a more complex
tune for two voices codified without using symbolic note names. Using this
technique you can even specify different velocities for each note (although
this example uses 0x64, dec.100 for all notes). The sample also uses running
status and knows how to cope with silences.
Regards,
Pedro