6d Don't knock to signal end of playtime (3 words) R?N?????E?? Is it RING THE BELL 7a British nocturnal type is to provide delivery B?W? Is it bowl (cricket delivery?) 21a Pop singer performed nothing D?D? is it DODO (If so why?) 11a Clever bit of cubism artwork S???? 12d A right time for skill ??? (is it ART - if so why/) 16a Grudge exprected by fellow coming back F?U? (is it FUED) 15a Released and about to be extravagent O???? 20a Apply force over wild celebration R?V?? (Is it REVEL )