Crossing solutions to the clues clash in eight of the squares. The correct letters to enter in the puzzle spell out, in grid order top to bottom, a name connected with the unclued solution to 17 16, which may help you solve these clashes, while still entering only real words.
About half way through the solve and with quite a few of the crossing letters in 17a, Bert suddenly guessed the theme of the puzzle – we already had a few of the clashing letters. A quick check on the possible clashes which we hadn’t found enabled us to complete the rest of the puzzle more quickly when Joyce remembered THE CLASH, who recorded the song at 17 16.
Given the title of the song – the clashing ‘I’s definitely go, but the others stay. The completed grid below and the highlighted cells show the clashes with I and the correct letter for entry.

An enjoyable solve – thanks Picaroon and we hope everyone had a Happy Christmas and New Year’s EVE.
ACROSS
6 Breakdown of relative after obsessive year (8)
ANALYS(I)S / ANALYSTS
SIS (relative) after ANAL (obsessive) Y (year)
9 Foreign address in rocky northern shore (6)
SENHOR
An anagram of N (northern) and SHORE – anagrind is is ‘rocky’
11 Impress with hot and good weather (7)
(I)NGRAIN / ENGRAIN
IN (hot) G (good) RAIN (weather)
12 Old impostors to put in entertaining places (7)
FA(I)TORS / FACTORS
TO inside FAIRS (entertaining places) – a new word for us
13 It helps you look and see my clue is wrong (3,6)
EYE MUSCLE
An anagram of SEE MY CLUE – anagrind is ‘wrong’
15 Catch or miss nothing (5)
LASSO
LASS (miss) O (nothing)
17,16 See special instructions (6,1,4,2,6,1,2)
SHOULD I STAY OR SHOULD I GO
22 Mythical maiden rested, returning her letters? (5)
(I)OTAS / LOTAS
IO (Greek mythical maiden) SAT (rested) reversed or ‘returning’. IOTAS are Greek letters.
24 Introduced one cultivated, welcoming two Poles (9)
INST(I)LLED / INSTALLED
I (one) TILLED (cultivated) around or ‘welcoming’ N and S (two poles)
26 Soldiers performing rites for old cavalrymen (7)
RE(I)TERS / RESTERS
RE (soldiers) and an anagram of RITES – anagrind is ‘performing’ – another new word for us
28 Amateur about to speak ill of millions in religious movement (7)
MAHDISM
HAM (amateur) reversed or ‘about’ + DIS (to speak ill of) M (millions)
30 For reporter, any editors will be necessary (6)
NEEDED
N E (sounds like any 0r ‘reported’) ED ED (editors)
31 Nearly get rid of can — there’s drink in it (8)
DEMIJOHN
DEMIt (get rid of) missing last letter or ‘nearly’ and JOHN (can)
DOWN
1 Were very hungry dean and reverend briefly out? (7)
RAVENED
An anagram of DEAN and REV (a shortened or ‘brief’ way of writing reverend) – anagrind is ‘out’
2 Bird some metres to the north (4)
MYNA
ANY (some) M (metres) written upwards or ‘to the north’
3 Alcoholic drink and food includes self-catering (6)
MESCAL
MEAL (food) around or ‘including’ SC (self catering)
4 Novice in love, slowing up (4)
T(I)RO / THRO
O (love) RIT (musical term for slowing) reversed or ‘up’ in a down clue
5 Day small boy gets a thrill (7)
FRISSON
FRI (day) S (small) SON (boy)
7 Developed the slogan for director’s technique (5,4)
ANGLE SHOT
An anagram of THE SLOGAN – anagrind is ‘developed’
8 Drink’s temperature not quite chilled (5)
TONIC
T (temperature) ON ICe (chilled) missing last letter or ‘not quite’
10 Faster runs in course (6)
AFTERS
An anagram of FASTER – anagrind is ‘runs’
14 Payment from Maori in skirt but no top (3)
UTU
tUTU (skirt) missing first letter or ‘no top’
16 See 17
18 Least interesting setter enters clad in antique fashion (6)
DRIEST
I (setter) inside or ‘entering’ DREST (old word for clad)
19 Half-hearted girl’s stories (3)
ANA
ANnA (girl) with only one ‘n’ or’ half-hearted’
20 Shopkeeper almost bags new coins (7)
FLORINS
FLORISt (shopkeeper) missing last letter or ‘almost’ around or ‘bagging’ N (new)
21 Troops tucked into rum, time for scrap! (7)
ODDMENT
MEN (troops) inside or ‘tucked into’ ODD (rum) and T (time)
23 Lose it on interrupting court favourite (3,3)
SEE RED
RE (on) inside or ‘interrupting’ SEED (favourite on a tennis court)
25 Not all accepting head of music department (5)
SOMME
SOME (not all) around or ‘accepting’ M (first letter or ‘head’ of music). The Somme is a French department.
27 Special police force turned over kind of cell (4)
STEM
S (special) and MET (police force) reversed or ‘turned over’
29 Maybe Glaswegian home around capital (4)
(I)AIN / HAIN
IN (home) around AI (first rate – ‘capital’)
Thanks to Picaroon and BertandJoyce
I enjoyed this but really struggled until I had a few of the clashes sorted. Then I noticed that it was likely that the clashes were all combinations of an ‘I’ and something else. That made me suspect that the other letters spelled out what was needed to be known. I guessed ‘The Clash’ from those I had and from then on I was in ‘Complete Control’. If I were in my old pad in Ealing rather than Connecticut, I could have begun with ‘London Calling’.
Unsurprisingly I learned a large number of new words.
I bet mc_rapper67 liked this a lot, even though he prefers Blondie [who doesn’t].
I thought this was a clever use of the song title. Much easier than the previous month’s puzzle (missing vowels).
I really enjoyed this challenge. I am a fan of THE CLASH – the song title used in this puzzle was on the juke box at the Student union in the eighties – and was played most nights in the bar where I actually met my wife! loved the cheek of the instructions with the (not so) hidden hint, well done Picaroon.
Sadly for us this was a dnf as I had casually entered ESTER at 22a thinking it was a simple hidden reversal. It took me a while to see that the letters in the reversal weren’t quite in the right order. In the meantime I had solved 20 down as TESTONS with TESTOS nearly being TESCOS. I couldn’t therefore come up with any ‘old cavalrymen’ with the right letters for 26a.
My instinct about TESCOS not being right was correct and I should have been looking for a fair shopkeeper and less obscure answer for the coins. D’oh.
The maiden in 22a (IO) was not directly known to me even though I should have been less ignorant as I knew the Saturn moon of the same name. The word with the corrected letter, LOTAS, is also a new one on me.
The South West corner did for me while the other quadrants were less tricky.
It was with great anticipation that I came here for the parsing so many thanks to you, BertandJoyce, for your explanations.
I enjoyed the challenge which was more accessible than the last puzzle (missing vowels) and a lot of fun so thanks to Picaroon (my fellow Clash fan?!!).
A super puzzle – I really liked the indication to the clashes, and was impressed at how the grid had been put together. Quite a bit easier than last month 🙂
Great puzzle that was fun to solve, and another incredibly impressive Genius grid fill.
My only slight criticism (if you can call it that) is that the enumeration of 17,18 gave the game away a bit too quickly. The song title jumped out at me with just a few crossers in place. If it had just been specified as “22, seven words” it would have been more of a challenge.
Many thanks to Bertandjoyce and Picaroon.
No problem Hamish/Soup@4. Still enjoyed the challenge of last month 🙂
We were lucky in seeing the song title early – I speculated that ?H???D followed by a 1-letter word might be SHOULD I, then Mrs Beaver immediately came up with the answer, and hence the 8 letters of the band, all of which helped a lot, but no complaints about that!
It was very ingenious that ALL the words, even those not entered, were valid, so hats off to Picaroon for a genius that was more fun than usual 🙂
Really enjoyed this – I am not a top-notch solver so it was doable but the last couple only fell towards the end of the month (much interrupted by festivities). As grid-fills go, I thought this was sheer brilliance, with the theme beautifully used. Many thanks to Picaroon for the entertainment (and the trip down memory lane) and to Bertandjoyce for the blog.
Sadly, I didn’t attempt this as I haven’t got a working printer at the moment. In fact, I realise now I could still have done it on laptop using Crossword Compiler to copy the grid (as I have been doing with some other puzzles), but I really like to do my crosswords when I haven’t got the laptop open. Might have a go at this month’s like that, nevertheless (although I haven’t looked to check if it’s suitable yet).
Thanks for the blog, Bertandjoyce, which at least meant I could appreciate the puzzle after the fact.