1: Singers in a special Tosca production (5)
2: British poet associated with gravity is having a merry time (7)
3: Real white, strangely, having more green? (9)
5: Having a specialized tax status, the result of a visit to an amateur tailor? (9)
6: Part of speech idealists rebuke (5)
7: Windbag has nothing on after dance? (7)
8: Rita Mears breaks wind near a plane (9)
13: Gets high by direct routes? (9)
15: Coming back to see old friends, painfully rein in gut (9)
16: Last brute buckles under counter arguments (9)
18: The last theologian inside to burn the cheese (7)
19: No, I save up for escape (7)
21: and 15 Novel alternative excised from huge spits (5,12)