You list all the pitch-changes that your notation distinguishes,
and then choose what symbols to use for each pitch pitch-change.
Transposition uses your defined pitches:
\transpose bes, c \music takes the difference between
bes and your pitch
shifts every pitch in
\music by that amount.
If the resulting pitches have an alteration with an entry
glyph-name-alist, that symbol is printed.
A missing entry generates a warning.
You can put as many alterations in
as you like.