I use LilyPond at a relatively low level. Mostly just to re-write single
parts, change clefs, transpose, etc.
A friend of mine, however, is a much-published composer who has written for
film, TV, high school and college bands, jazz charts, etc. We got to
talking about various notation software because he mentioned he was having a
problem with Sibelius. I regaled him with the horrific problems I
personally had with a completely legal copy of Sibelius when I got a new
computer -- the code refused to believe it was legal thereafter.
I have been recommending he give LilyPond a try. But I've never used
LilyPond at the high level he works in.
My question is this: are there many working professional composers and
arrangers who rely on LilyPond as their first choice for notation software?
I know there are a lot of amateurs like me -- but I'm wondering if there
are pros out there who use LilyPond daily at a high level for multi-part
scores, etc.