The music is one part of the show that actually has been improving. It started terrible in the movie with the techno and ethnic music, but lately it has gotten a more SW and Williams feel.
On the Mortis arc, the main theme of those episodes seemed to be a variation on the Force theme, the Force theme was heard a couple of times and even Qui-Gon's theme from TPM (yes he has a theme) made an appearance, it was nice they brought it back even if it's a rather obscure theme.