A rare outing for the full-perimeter (4×15-letter answer) grid. Although that does mean that quickly solving either 1A or 1D offers generous checking and a flying start.

Across
1 GENERAL ELECTION - cryptic def’n, although it could of course apply to most kinds of ballot (except for those featuring hanging chads or ink-stained thumbs).
9 NO(THIN)G - “drink that’s inherently watery” is the slighty indirect container/contents indicator.
11 W(E)AVE - “roller” in the oceanic sense.
12 CONTRALTO - Central (with o for e) + to
13 T(HERE)UP,ON
15 CLYDE - hidden
18 STEEL BAND - good surface reading.
23 MACH,O - “sonically still” suggests zero x speed of sound (or Mach 0).
24 I,MAG(-az)INE - The whole “first” and “last” alphabetical conceit, to denote A and Z, generally tends to get stuck in my craw.
26 DEFINITE ARTICLE - (ain’t electrified)*

Down
1 GONE WITH THE WIND - Go+New+It+H(Thew)ind. A lot quicker to solve than to deconstruct!
4 LO(GI)C - G.I. in col(rev)
6 CEDAR - referring to the national emblem of The Lebanon, which I believe still graces its national flag.
8 NITROGEN DIOXIDE - hidden, or at least its chemical symbol (NO) is.
14 PE(STILE)NT - the last to go in for me, as I had some hesitance reconciling the definition with “vexatious”.
15 COLUMNIST - A nice idea (attempting to finesse The Fourth Estate with Fifth Column) but just seems to lack that je ne sais quoi that differentiates the truly great clues from the remainder.
19 ARCH,AIC - the phrase “old hat” always strikes me as being rather twee. I suppose that it’s, arguably, rather old hat itself these days.
21 BA(I)RN
22 HOO(-c)H,A - Maybe a touch parochial for non-Brit solvers? Hoo-ha and kerfuffle are the two British words guaranteed to always raise a laugh from my (all-American) wife.

Although there are one or two I’m not sure about, this was not one of Dac’s most difficult. Which doesn’t prevent it from being well up to his usual standard. Is there some kind of a cinematic theme?

So glad the luck of the draw gave me this benign but pleasant Araucaria to blog rather than yesterday’s Gordian nightmare.

Still short one answer and my explanation of some of the wordplay is imperfect, so some scope for audience participation if you are so minded.

1 CONDUCT MEDAL : sounds like meddle

9 (l)INER-R-OR : there’s an extra “R” I can’t quite explain - but that could be self-referential I suppose !

10 PRESTO-N

11 TANG-ERIN-E

12 TAMBO(rine) : African leader, Oliver Tambo

13 NO-SH : ie. no “Sh!!!”

14 Despite having all the letters I haven’t got this yet

16 UNWIN-NABLE : Professor Stanley Unwin was a comedian and Elbans live on Elba I guess

19 A-C.I.D

20 SKIER - either a cricket ball hit into the sky or someone sliding on snow

21 CIVIL YEA-R : A church calendar that does begin on Lady Day (25th March). Will be humming Billie Holiday tunes today (nickname ‘Lady Day’)

23 EC(TOP-I)A - guessed it was a word from ectopic pregnancy and ectoplasm.Haven’t quite settled on a coherent reason for the wordplay though “Top hat” “Ace” backwards ?

24 RINGLET - contained in the tex, and I had to check there was a Ringlet Butterfly

25 SERVICE ORDER - connection with 7 is obvious if you know what DSO stands for

DOWN

1 CLEAN AS A WHISTLE : (WALLACE SHINES AT)*

2 NURSE : initial letters of the clue

3 U-PRAISE

4 TO-PG-EAR : A lodger was a “Paying Guest” (PG) in Araucaria’s day, pretty obscure today though

5 ELEC-TORS : CELEbrities in reverse with a common crossword word for mountains

6 AUTOMATIC TELL-ER : reference to William TELL

7 DISTINGUISHED

8 I(NCO-N-SIDE)RATE

15 AN-DROP-OV

17 AR-CH(A)IC : can anyone explain the initial “AR”, or have I totally missed the point ?

18 LIV-OR-NO : LIV is 54 in roman numerals

22 LINED - wrinkly, and warmer in the sense of a “lined jacket” which has a lining in it. Had a lot of fun trying to make “gonad” fit the clue as well as it fit the letters ??N?D .