Across:
1 Symphonist dismisses mint (‘symphonist’ dismisses ‘mint’ = syphos = HYSSOP) or aromatic plant from mint family (HYSSOP),
4 Sidney (S-ID) admits pressure (-P-) to extend credit (-LEND-) (SPLENDID) outstanding (SPLENDID),
9 Use an (use an = NAUSE-) anomaly (= anagram indicator) to go to a (-A) (NAUSEA) medic to diagnose this (NAUSEA),
10 Doctor (-GP-) loses the head (p) with churchwarden (churchwarden clay ‘pipe’ without ‘p’ = -IPE-) in public house (BA-R) (BAGPIPER) playing Scottish music (BAGPIPER),
12 Clip of (e) those characters in 21 across (‘crime’ without ‘e’ = CRIM-) popular (-IN-) with gangsters (Als = -ALS) (CRIMINALS) doing time (CRIMINALS),
13 It’s the same old story (RERUN) – insurer is missing (‘insurer’ ‘is’ missing = nurer = RERUN),
14 18 across opens (‘fruit growing’ opens = FRUIT) church (-CH-) in American state (Maine = MA-INE) (FRUIT MACHINE) synonymous with the pulling power of gamblers in Las Vegas, for instance (FRUIT MACHINE),
18 It’s forbidden in the garden (forbidden FRUIT in the Garden of Eden) to start grumbling (start ‘grumbling’ = G-) and arguing (-ROWING) (FRUIT GROWING) or creating the conditions for sour grapes perhaps (FRUIT GROWING),
21 Caught (C-) on the border (-RIM-) with drugs (-E) (CRIME) and is investigated by the guards (CRIME),
22 Strange (= anagram indicator) CIA terms (CIA terms = ARM-STICE) covering first (-I-) (ARMISTICE) military truce (ARMISTICE),
24 Diamonds (-ICE) and cocaine (C-) hidden by playboy (rake = R- -AKE) (RICE CAKE) in a crunchy diet snack (RICE CAKE),
25 A number of waves (SERIES) sound (= homophone indicator) terrifying (‘eerie’ = ‘erie’ = -ERIE-) in boat (S-S) (SERIES),
26 Part payments (DEPOSITS) for butcher’s (= anagram indicator) topsides (topsides = DEPOSITS),
27 Works at the gate (plays at The Gate Theatre = PLAY-S) guarding a (-A-) (PLAYAS) space for loungers in Barcelona (loungers on Spanish beach / PLAYAS).
Down:
1 Restrain (HANDCUFF) American (-A-) supporting the milk producers (National Dairy Council = -NDC-) in a bad mood (huff = H-UFF) (HANDCUFF),
2 Most of (y) the analysis (‘study’ without ‘y’ = STUD-) on promissory notes (IOUs = -IOUS) (STUDIOUS) is academic (STUDIOUS),
3 Some uplifting (= reversal indicator) worthwhile boycott (some ‘worthwhile boycott’ = ‘ilebo’ is ‘reversed’ = OBELI) of daggers (OBELI),
5 Sticks close to convention (PLAYS THE GAME) park (P-) and puts down (-LAYS down) most of them (most of ‘them’ = THE) for amusement (GAME) (PLAYS THE GAME),
6 Ten operas (ten operas = ESPERANTO) rewritten (= anagram indicator) in international language (ESPERANTO)
7 Put out (DEPORT) short (n) study (‘den’ without ‘n’ = DE-) for the drinkers to consume (-PORT) (DEPORT),
8 Throwing down the gauntlet (DARING) to relative (DA-) in Waterford (-RING) (DARING),
11 Beastly African cover-up (SAFARI JACKET) of outing for the game (SAFARI) with one of The Blazers (JACKET) (SAFARI JACKET),
15 Number associated with crowd (“two’s company, three’s a crowd” = THREE) building (= anagram indicator) case (case = ACES) (THREE ACES) for risk takers being dealt a strong hand (THREE ACES),
16 One (-I-) foolish person (-NIT-) entering Vichy (Vichy) misses hotel (h) (‘Vichy’ without ‘h’ = VIC-Y) (VICINITY) in the surrounding area (VICINITY),
17 See gross (see gross = OGRESSES), crazy (= anagram indicator) big cannibals (man-eating female giants = OGRESSES),
19 Shaking like a leaf (SCARED) chopping up (= anagram indicator) cedars (cedars = SCARED),
20 Caught (-C-) copper (-CU-) cutting joint (hip = HI-P) (HICCUP) – it’s a minor setback (HICCUP),
23 Jeer coming out of jewellers (‘jeer’ coming out of ‘jewellers’ = wlles = SWELL) with dandy (SWELL).