Cryptic crossword No 2,597

As ever, comments are greatly welcomed.

Some good stuff here - my favourites included 7a, 4d and 22d. I've got a couple of observations in the reply.

I enjoyed this a lot, Baz, and you have packed a lot into your grid. Orinoco makes a fair point about 'singular' but one does get used to it. Lots of neat and enjoyable clues inc 7a, 13a, 14a/17a, 27a, 6d, 23d (COTD). Thanks. PM