Rickye, 1 down is a variant of a word that means a flourish of trumpets and is thematic. The piper with horns is a god associated with pipes, followed by a 7 letter word for shows off (think soldiers on xxxxxx). Then change all Ps to Fs
12d - My answer is "someone who fits ribbed borders" and I assume the K is removed from "masks" but 'mass' doesn't seem to fit anywhere in my answer, or "apparently" for that matter?
21d - where does the E come from? It doesn't seem like it can be added to "drum" and "beat" looks like the anagrind so I can't see where it comes from?