Suggestion: new property "filename" for MIDI output

[Manuel Bernhardt]

Dear Lilypond team,

there seems to be no possibility to influence the output of the MIDI files, is 
there?

As I notate many percussion staves, I often have the problem that one MIDI file 
for a whole African rhythm is much too less. Therefore, I additionally add some 
scores which only contain the MIDI output for all the pure voices.

Now, imagine you have singing, 2 accompaning Djembé, 3 basses and 1 solo Djembe 
for the normal rhythm. Additionally, the basses go into something called 
echauffment very often, where the solo Djembe calls the basses and they change 
their rhythm.

If the singing and the other Djembé also change (="worst case"), you have 14 
MIDI files for the pure voices. I think work was much easier if I could give 
the MIDI file an additional property "filename" (or simply use the Staff's 
instrumentname, whatever) and the resulting MIDI files were like:
- MyAfricanRhythm-DjembeOne-Rhythm.mid
- MyAfricanRhythm-DjembeTwo-Rhythm.mid
.
.
.
- MyAfricanRhythm-DjembeOne-Echauffment.mid
- MyAfricanRhythm-DjembeTwo-Echauffment.mid
.
.
.

instead of 
- MyAfricanRhythm.mid
- MyAfricanRhythm-1.mid
- MyAfricanRhythm-2.mid
.
.
.

Is there a possibility to do that?
Or, if not, to make it possible in future versions?

Best regards,
Manuel

P.S.: I noticed the same for more than one \bookpart: the created PDFs are 
called MyAfricanRhythm.pdf, MyAfricanRhythm-1.pdf, MyAfricanRhythm-2.pdf etc.