Across:
1 Rotating (= reversal indicator) switch (on = -NO-) in Cork (CA-P-) yard (-Y) (CANOPY) provides shelter from the sun (CANOPY),
4 African (EGYPTIAN) tangy pie (tangy pie = EGYPTIAN) carved up (= anagram indicator),
9 Circulates missing tale (‘circulates’ missing ‘tale’ = circus = CIRCUS) – the one with the clowns (CIRCUS),
10 Serves up (= reversal indicator) vegetable (leek = KEEL) range (oven) mostly (n) (“oven” without “n” = OVE-) from recipe (-R) (KEEL OVER) and pass out (KEEL OVER),
12 Use one’s research skills to discover (TRACK DOWN) what the musicians produced (TRACK) with The Blues (DOWN) (TRACK DOWN),
13 A Dior (a dior = RADIO) dress (= anagram indicator) – a medium perhaps? (RADIO),
14 Got pregnant (-CONCEIVED) after being unwell (ILL-) (ILL-CONCEIVED) and it wasn’t planned with any great thought (ILL-CONCEIVED),
18 Outfit (-RIG-) follows (= positional indicator) whistleblower (referee / REF-), Clio’s sister (ERATO-), from the start, religiously (from the start ‘religiously’ = -R) (REFRIGERATOR) keeping things cool (REFRIGERATOR),
21 Lean or muscular type (SINEW) of new (= anagram indicator) wines (wines = SINEW),
22 Lake (Lake GARDA) bar (BAN-) near delta (-D) (GARDA BAND) plays the national anthem before big matches (GARDA BAND),
24 Acute (CLEVER-) hospital ward (-ER) (CLEVERER) is more resourceful (CLEVERER),
25 Quarrel (F-IGHT) is over writing (-R-) (FRIGHT) that will give one the heebie-jeebies (FRIGHT),
26 One of those looking on the bright side of life (optimist) nearly (t) (‘optimist’ without ‘t’ OPTIMIS-) gets married (-M) (OPTIMISM) in Great Expectations (OPTIMISM),
27 Fear and trembling (TERROR) on first tee (first ‘tee’ = T-) leads to inaccuracy (-ERROR) (TERROR).
Down:
1 Jasper is not part of practical jokes (‘Jasper’ is not part of ‘practical jokes’ = cticalok = COCKTAIL) in Manhattan? (COCKTAIL),
2 As a rule (NORMALLY), Molly ran (Molly ran = NORMALLY) Review (= anagram indicator),
3 Local bottle (PLUCK) of spirit? (PLUCK),
5 Olive (GREEN) grasses on local (FINGERS) (GREEN FINGERS) with skills essential to the plot (GREEN FINGERS),
6 Beastly type who can stand up for himself (POLAR BEAR) is typical of 17 down (POLAR BEAR is a ‘predator’),
7 ANC leaves in advance (“ANC” leaves “in advance” = idvane = INVADE) of storm (INVADE),
8 It’s going to be tight (NARROW) in new (N-) Dart (dart/missile = -ARROW) (NARROW),
11 Live music lovers (CONCERT-GOERS) interested in performance by 22 across, for example (CONCERT-GOERS interested in “garda band” for example),
15 Finished (OVER-) work (-W-) on high (-H-) tree (-ELM) (OVERWHELM) in swamp (OVERWHELM),
16 Funny (STRANGE-) writing (from 3Rs = -R) (STRANGER) in The Outsider (STRANGER),
17 Is a stalker of The Animals (PREDATOR) and Teardrop (teardrop = PREDATOR) Explodes (= anagram indicator),
19 Nutcase (PSYCHO) starts pre-school year (starts “pre-school year” = PSY-) at church (-CH-) order (-O) (PSYCHO),
20 Shoot up? (INJECT) Give it a shot! (INJECT),
23 Reviews (= reversal indicator) English (-E-) chapter of history (era = A-RE) about key (music key -G-) (AGREE) match (AGREE).