choice of words: (de)crescendo on items with specified volume

[Mark Polesky]

compiling this...
   { g \f\< a b\p c }
...generates this message...
programming error: (de)crescendo on items with specified volume
...but only when a \midi { } block is present.

Shouldn't it be "unspecified volume"? A cresc on an item with a
specified volume would seem to be what MIDI wants. Anyway, I 
propose rewording the error message to something like:

MIDI warning: impossible or ambiguous (de)crescendo

Any thoughts?
- Mark