Unclued lights are words from a poem, its author and a relevant location. Elsewhere, ignore two accents.
 

Across

7    Music like reggae from Saskatchewan (3)
11    Carriage policeman pulled over beside hedge (6)
13    Judge meets drug addict who’s declining (7)
15    Ionian cardinal crossing Iowa (5)
16    Strong pickle’s sound (5)
17    Seminary keeps beer for Arab? (6)
18    Woman is sickly Australian (5)
21    Colour of rock bordering river (5)
22    Thoroughly noble bard’s cap (7)
27    Cover of books French author penned (7)
29    Silent historian ignores us (5)
30    Funky river has aquatic beasts (6)
32    One round child with love for Mexican snack (5)
34    Curved shaft Athens developed (6)
38    Composer from Ocean State hiding very big crime (7)
39    Plant to get rid of smothering acres (6)
40    Chief officer once more not at home (3)
41    Lively gripping granny runs away with group of giants (11, three words)
 

Down

2    Fine apartment within court is swell (8)
3    Poet’s unfairness having snubbed girl with defect (9)
4    Old PM riled miners with second Durham talk? (12)
5    Tense husband wins disputes in Gretna (7)
6    Our flyer hyped up fine powder (8)
8    Ancient old woman with no daughter to frighten (4)
9    Jade restored very classy old stuff (6, two words)
10    Trees only next to river (5)
12    Kingly chap against all risks in marketplace (6)
14    Peter afflicted with another bug (12)
21    Dress gnome embroidered with cash (9)
23    Cost of present (diamond anklet) (8, two words)
25    Lecturer goes after London museum wrecker (6)
26    Driving off tee leaves twinge of pain (7)
28    Irish lass inhales a gas (6)
31    Sarah’s athletic dance (5)
33    Entrances to drowned valley (5)
35    Recorder very short with leader of anarchists (4)
 
A first prize of £30 for the first correct solution opened on 28 May. 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 2358, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.