In rP19887, Omri added the new song "Tale of Warriors", but it is not used in the game yet.
It was proposed to add it as a civ independent peacetime track after some time or the first battle passed (probably because the song is somewhat epic and rather fits to a great empire).
When looking at the civ files and music.js, we can see that
(1) two prior tracks are unused too, which is really a loss:
(2) The song The_Hellespont.ogg is used 4 times while all other songs are used once to twice.
(3) A handful of civs repeat only two peacetime songs, while most use 3 and brit and gaul have 4, while many songs occur for only one civ.
With the patch applied:
- Every civ will have at least 3 songs
- Every song will be used.
- No song will be used by more than two civs.