This turned out to be harder than it looked on first reading. Thanks Aardvark.
The grid looks like a pangram to me.

| Across | ||
| 1 | INQUISITOR | One questions popular Parisian who organised riots (10) |
| IN (popular) QUI (who, in French) then anagram (organised) of RIOTS | ||
| 6 | DRAB | Dull-brown bones seaman found (4) |
| DR (doctor, nickname of Bones) with AB (seaman) – “found” links DR and AB, they have found each other, they have met | ||
| 9 | CHILDBIRTH | Labour adherent assigned place in auditorium (10) |
| CHILD (adherent) with BIRTH sounds like (in auditorium) “berth” (place) | ||
| 10 | YUAN | Your aunt regularly distributed money abroad (4) |
| every other letter (regularly distributed) of YoUrAuNt | ||
| 12 | PALAEOLITHIC | Political head cut short, having broadcast for a long period (12) |
| anagram (having broadcast) of PILITICAL HEAd (cut short) | ||
| 15 | BALSAM FIR | It’s a piece of cake taking over troubled firm’s large N. American plant? (6,3) |
| A SLAB (piece of cake) reversed (taking over?) anagram (troubled) FIRM – this explanation doesn’t feel quite right to me | ||
| 17 | GONNA | Shortly intending to log on? Name only partly needed (5) |
| found inside (only partly need) loG ON NAme | ||
| 18 | TANGO | Dance beat ending with vigour (5) |
| TAN (beat) then (ending with, followed by) GO (vigour) | ||
| 19 | OVERLYING | Placed on top of float, head shaven, telling stories (9) |
| hOVER (float) missing first letter (head shaven) then LYING (telling stories) | ||
| 20 | THE BEACH BOYS | Pop group in ancient city absorbing movement of Bach extremely openly (3,5,4) |
| THEBES (ancient city) contains (absorbing) anagram (moving) of BACH and OpenlY (extremes of) | ||
| 24 | IRON | Press club (4) |
| double definition | ||
| 25 | CANIS MAJOR | Cooler island attracts important group of stars (5,5) |
| CAN (cooler, prison) IS (island) with MAJOR (important) | ||
| 26 | SO-SO | Indifferent appeal by Yorkshire’s number two (2-2) |
| SOS (an appeal, for help) then yOrkshire (number two, second letter of) | ||
| 27 | ANGLO-SAXON | Weird slogan by US feller using old language (5-5) |
| anagram (weird) of SLOGAN then AX (axe in US, a feller) and ON (using) | ||
| Down | ||
| 1 | ITCH | Long throw, releasing power (4) |
| pITCH (throw) missing P (power) | ||
| 2 | QUIZ | Grill midsection of squid, an unspecified amount (4) |
| sQUId (midsection of) then Z (an unspecified amount, in a formula) | ||
| 3 | INDIANA JONES | Legendary adventurer one’s seen supporting state leader in jeopardy (7,5) |
| ONE’S follows (seen supporting, in a down-light) INDIANNA (state) and Jeopardy (leading letter of) | ||
| 4 | IBIZA | International business associated with a part of Spain (5) |
| I (international) BIZ (business) A (associated) | ||
| 5 | OUTSOURCE | Obtain goods from external supplier, determined course will change (9) |
| OUT (determined) then anagram (will change) of COURSE | ||
| 7 | ROUGHING IT | Living austerely in reduced French house with uncut grass (8,2) |
| IN then GITe (French house, reduced) follows (with) ROUGH (uncut grass, on a golf course) | ||
| 8 | BANK CHARGE | Financial expense causing row and domestic upset, say (4,6) |
| BANK (row, a bank of switches for example) and CHAR (domestic) EG (say) reversed (upset) | ||
| 11 | KINGSLEY AMIS | Cambridge college master probing easily unsettled novelist (8,4) |
| KINGS (Cambridge college) then M (master) inside (probing) anagram (unsettled) of EASILY | ||
| 13 | OBSTETRICS | New strobe, right away, reportedly deceives medical department (10) |
| anagram (new) of STrOBE missing R (right) then TRICS sounds like (reportedly) TRICS (deceives) | ||
| 14 | SLANDEROUS | Malicious sons acquire suspect euros (10) |
| S (sons) LAND (acquire) then anagram (suspect) of EUROS | ||
| 16 | FOOD CHAIN | Fellow rings daughter to secure hierarchy (4,5) |
| F (fellow) O O (two rings) D (daughter) then CHAIN (secure) | ||
| 21 | BRILL | Small stream with bass and other fish (5) |
| RILL (a small stream) follows B (bass) | ||
| 22 | AJAX | A sailor’s discussing ancient hero (4) |
| A then sounds like (discussing) “jack’s” (sailor’s) | ||
| 23 | WREN | Yank taking out Chinese bird (4) |
| WRENch (yank) missing (taking out) CH (Chinese) | ||
definitions are underlined
I write these posts to help people get started with cryptic crosswords. If there is something here you do not understand ask a question; there are probably others wondering the same thing.
AJAX and QUIZ were my first couple in so it looked as if a pangram was on the cards from early on.
For what it’s worth, I parsed the previously unheard of BALSAM FIR as you did, but see what you mean about ‘taking over’. I had to think a bit to parse ROUGHING IT and didn’t know CHILD for ‘adherent’.
I liked INDIANA JONES and the association of Bach and THE BEACH BOYS.
No piece of cake, however parsed, for me either, but satisfying to get there in the end
Thanks to Aardvark and PeeDee
Only looked to see if it was a pangram (it is) after completion. A well-constructed crossword apart from BALSAM FIR which doesn’t work for me even though the answer was clear once I had checked such a tree existed.
Thanks to Aardvark and PeeDee.
Yes PeeDee 1a and 1&2d did seem like it was going to be a breeze, but it turned out to be one that stiffened up (how do breezes stiffen up!?) as it went on. As well as those mentioned I also liked DRAB as it took me a while to remember BONES = DR and GONNA (horrible word) was well hidden and defined. I too struggled with BALSAM FIR – at least Aardvark was kind enough to define it as a NA plant. Thanks to setter and blogger.
Thanks to Aardvark and PeeDee. I struggled with BALSAM and DRAB and had trouble with CHILD as adherent.
Thanks to PeeDee and Aardvark
This took a bit of puzzling out. As with others I was misled (misdirected?) by the easy start and almost stopped as I thought it might not be much fun.
But it seems to me that some of the difficulty was caused by some very “stretchy” usages:
6a FOUND is really there just for the surface, and, I think only relates to SEAMAN rather than it being a link word
9a CHILD = ADHERENT?
15a TAKING OVER, again, just for the surface
25a ATTRACTS ditto
4d I took ASSOCIATED WITH to mean “next to” A, with PART OF SPAIN being the definition
5d DETERMINED = OUT?
21d DISCUSSING = DISCUSSED?
I enjoyed the unpicking though
Really enjoyed this, but hate the word (is it really a word?) “gonna”. Some very tricky clues.
I am surprised that no one has commented that 24a Press club (4) is an old chestnut. I was thrilled no end when I came across this in a crossword in a local newspaper decades ago. I was to learn much later that the puzzle it appeared in was by Roger Squires syndicated by First Features. He himself may have repeated it in his puzzles to other newspapers with due ‘spacing out’. And of course we see it occasionally in puzzles by others. Seasoned solvers when they come across it may mechanically write in the answer with nary a smile on their lips.
Who used it first? We would never know!
I have no complaint,though! If today this clue has given pleasure to someone, so be it.
Rishi – often I can’t remember clues I solved last week let alone ones that appeared decades ago!
AFWard & others – I had a little shudder when writing in GONNA too. Chambers gives it as mainly US and I think it sounds much better when used in American English where it really belongs. I can’t imagine “going to” sounding better than “gonna” in a Film Noir or a blues song.
Thanks Aardvark and PeeDee
Entertaining puzzle with the usual variety of clue types and a bit of general knowledge required. Didn’t stop to see the pangram.
Thought that the word play in KINGSLEY AMIS and THE BEACH BOYS were both quite clever.
Finished with ROUGHING IT (had to dig deep for the French house), BANK CHARGE and PALAEOLITHIC (which took ages to see that it was an anagram).