In eight clues, cryptic indications omit reference to parts of answers; these parts must be highlighted, to reveal the title (two words) of a track on 1D (two words) by the 12 (two words). The title in question defines the other unclued lights.
 

Across

 
1    Drain ground in place behind square architectural space (8)
5    Dust and damage around hermitage (6)
9    Delay going back aboard to set sail (10)
14    Dislike ignoring odd characters, being kind (3)
17    Party without depth led by cold fish (5)
20    Lolling, for instance, pair violated law (7)
22    Cry, heat being bad for sailor (7)
24    Lock in corrupt and petty king (7)
25    Love note hidden (5)
26    Colourless matter, formality without energy (5)
28    Verse form can advance (7)
31    Chap, reverse of rational, in chains (7)
33    Scrub grand debate about independence (7)
37    Ballot box capturing soul of town (5)
38    Green area lost to some extent (5)
39    Little branches united and left bound by fibre (6)
40    Bounce about in saddle (3)
41    Ritual seat fashioned in glassy stone (10)
42    Perfume in kitschy presentation (6)
43    Ineffectual batting by learner during game (8)
 

Down

 
2    Silly confusion in wood (5)
3    Sioux dispatching a robber (6)
4    Trouble rising after one long series of woes (5)
6    Lashed saint finished dead (7)
7    Boat sped in front of buoy (6)
8    Roguish advance, not married (4)
10    Hydrocarbon constant in a way (6)
11    Made rough version of road scene (9)
13    Flower laid as arranged outside church (8)
15    Answer dummy if nothing else (7, two words)
19    Pueblo sheep party (9, three words)
23    Get tense in disgrace (7)
27    Constant attention keeping sail up (7)
29    Hell on highway (6)
34    Note carrying appeal for belief (5)
35    Judge electronic messenger (5)
36    Bribe lawyer and be quiet (4)
 
A first prize of £30 for the first correct solution opened on 4 April. There are two runners-up prizes of £20. (UK solvers can choose to receive the latest edition of the Chambers dictionary instead of cash— ring the word ‘dictionary’.) Entries to: Crossword 2251, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.