Re: [fluid-dev] How to change the instrument:channel assignment when playing a MIDI file

[David Henningsson]

On 07/10/2013 04:05 AM, Dave wrote:
> Hello,
>
> Fluidsynth newbie here. But thanks to some help from the wonderful folks
> in this group (especially GrahamG), and thanks to the excellent software
> design, I’ve been able to programmatically create mp3’s.
>
> I’m stuck on what is probably a trivial task, but I haven’t found the
> solution. I can play a midi file using a standard Soundfont from the
> command line, as follows:
>
> “fluidsynth fluidr3_gm2-2.sf2 mymidi.mid”
>
> But this uses the default channel:instrument assignments, which for this
> particular soundfont is “Yamaha Grand Piano” for all channels except the
> drum channel 9. I am trying to figure out how to programmatically change
> the instrument assignment.
>
> I created a simple configuration file, as follows:
>
> “load fluidr3_gm2-2.sf2
>
> prog 0 10”
>
> This assigns the “Music Box” instrument to channel 0. If I execute the
> following command: “fluidsynth –f fluidconfig.txt”,  I can see that
> channel 0 is in fact changed (by using the “channels” command.
>
> But if I try to BOTH change the instrument assignment AND play the midi
> file from the command line, i.e. “fluidsynth –f fluidconfig.txt
> mymidi.mid”, the midi file plays but the instrument assignment doesn’t
> occur, it still uses the default Yamaha Piano for channel 0.
>
> Is there a way to do both?

First, check the player.reset-synth setting, you might want to turn it 
off because it resets everything back to piano (and drums) every time 
you load start playing a midi file.

Second, you need to make sure mymidi.mid does not contain 
instrument/channel commands in itself. If both you and the midi file try 
to set the instrument for a channel, whoever does it later in time will 
override the former.

// David