A pleasant, gentle stroll today with nothing too 13ing, but I think there is an error in one of the clues (20dn) unless my parsing is incorrect.
It became clear quite quickly that the ‘A’ in twelve clues stood for ‘anagram’. This made the puzzle much easier as it meant that these twelve clues had two sets of wordplay, though it did result in rather a lot of anagrams overall as this device had also been used regularly elsewhere.
Across
1 BASMATI *([l]AMB ASTI)
5 TSARINA SARI (dress) in ANT (worker) reversed & *(ARTISAN)
9 STONE cd & *(ONSET)
10 CANTINESS *(ANTIC) NESS (head) & *(INCESSANT)
11 NOTARISES NOT ARISES (doesn’t originate apparently) & *(SENORITAS)
12 EXTRA X (unknown) in *(TEAR)
13 TACKS homophone of ‘tax’ (levy)
15 ASSERTION *(NOTARISES) & A NO 1 (top class) TRESS (lock) reversed
18 STRONG TEA *(TARTS GONE)
19 MUSIC M[elodies] U[nder] S[olti] I[n] C[oncert]
21 NEWER hidden in ‘linguiNE WERe’
23 DIPLOMACY DIPLOMA (university award) C[ivic] Y[outh]
25 TAROT CARD A (ace) in TROT (red) CARD (joker)
26 SACRA SACRA[ments] (half the rites)
27 ARTISAN [p]ARTISAN (beheaded blind adherent) & *(SINATRA)
28 SATISFY TIS (it’s poetic) F (force) in SAY (for example)
Down
1 BASINET *(BEST IN A)
2 SPORTS CAR SPORT (diversion) SCAR (mark)
3 AMEER A M (large number) EER (always)
4 INCESSANT *(CANTINESS) & SS (ship) in *(ANCIENT)
5 TONES dd & *(STONE)
6 ASIDE FROM *(DIORS FAME)
7 INERT NER[o] (emperor loses nothing) in IT
8 ABSTAIN AB (sailor) STAIN (shame)
14 SENORITAS ONES reversed RITAS (girl’s) & *(ASSERTION)
16 STAMPEDES *(PESTS MADE)
17 INSTANCES IN (popular) STANCES (positions) & *(INCESSANT)
18 SINATRA hidden in ‘memorieS IN A TRAnce’ & *(TSARINA)
20 CRY-BABY BY reversed in *(CAR) BY – there is no reversal indicator for the first ‘by’ and ‘in car crash by’ cannot indicate an anagram of ‘car by’. This problem would have been resolved had the clue been “….. in crashed car, by and by”.
22 WORST WORST[ed] (fabric young Edward removed)
23 DRAWN DR (doctor) AWN (beard)
24 ONSET *(TONES) & ON (go-go) SET (group)
Thanks very much for your blog, Gaufrid.
For 20dn, I think your parsing and comments are quite correct.
I also think a definition is missing in the clue for 4dn.