Thanks, Malone.
I've got the theme and a few titles now, but have a clash in the bottom right.
I've got 32a) beginning EGF _ _ _ but no word begins EGF as far as I know.
Yet 21d, 28d and 29d all seem to parse and fit. I suspect my error is in 28d, yet the nagara drum shortened gives me a word which does allude to George Harrison's inspiration.
Clashing Clue is:
32a) One finds these insects grow, developing large forewings.