If you meant you spelt 22D wrongly, lynbejack, I did the same! Maybe that's why 23A is proving difficult to some. I have it down as an equal legal pairing, teenieleek.
Can anyone confirm 27a looks like this: D?U?
............and if so, can only think of drum & bass, but what's bass got to do with the clue?
Prob. barking up trhe wrong tree altogether --- help!
Hurrah, finished at last, 27 is clever - it is musical. Don't get 25 down really but only one possible answer now. Any more hints required before I go? (she asked smugly)