Stuck on a few this time-
9d: "Suffer to accept stave for type of old mass?" (6) -a-o-y Searches in the web with those letters doesn't throw up any mass matching those.
8d: "British pop star mostly emboldened" (6) s-e-l- I thought Shelia but she is French.
28a: "Failed to notice obscurity in sound" (6) -i-s-r I thought of hisser or perhaps missed, but I'm sure the last r is correct. Cannot make anything fit the clue.