Many thanks to all. One last one :- Songwriters using enclosed rhyme scheme (4) A?B?. I suspect the answer is ABBA (songwriters) plus enclosed rhyme scheme ABBA where lines 1 and 4 of a poem or song rhyme as do lines 2 and 3. My problem with this is that I have always understood it was an absolute rule for the Times crossword never to make reference to celebrities/composers/poets/and people in general who are still alive. Have I got this wrong or has this "rule" recently been changed?
If memory serves, Dean Mayer (our own user "anaxcrosswords") mentioned that the rule has always been relaxed for the Sunday puzzle - perhaps that has been extended to the Saturday one as well?