Would it be possible to include letters in the track number field?
I have a plenty of vinyl rips and it would be nice to number them A1, A2, B1, etc..
I can write letters in that field, but after saving they are discarded.

(Yeah, I know, I could label them as CD1, CD2, then by track number on the side of vinyl... but it's not cool!)

I'll probably add an option to make the track field a string field, it should be easy to do.
Alternatively I could add an optional "side" field

i would vote for an additional field rather than making the track-field string, it just helps with the typos and all... (and even though i also have quite a few rips from vinyl i have to say that it's not such a common problem.)

I know, it just sounds like a whining of some sort... If everyone would request some feature which only a couple of humans use it, gmb would become too bloated and complicated.

Well, if you decide to add it, my pedantry would overload  :)