## Sine Qua Non by Shackleton

### Puzzle explanation

Misprints in clues spelt “Dot one’s Is and cross one’s Ts” and “Iddy-umpty” (see the table below), hinting at reading Is as Morse code dots and Ts as dashes in the normal clues. This yielded “Must it be?” and “Muss es sein?”, a question posed by Beethoven in his Quartet in F major, Op 135. The penultimate element in the first version (B = –•••), and three elements with identical material (L = •–••, F = ••–•, and V = •••–) are all described by “paeon” (a foot of four syllables, any one long, three short). B, L, F and V each occurred once in the grid, and all needed to be highlighted along with (the current entry) “major”, spelling out LVB (representing Ludwig van Beethoven) and F major. The element V suggested taking the fifth letter of the fifth word in each normal clue to give “diametric exchanges” which, when applied to “paeon” (and the diametrically opposed letters in the grid), resulted in “dit, dit, dit, dah”, the opening notes of “The Fifth (Symphony)”, and the Morse code for V. Finally F major needed to be changed to C minor, the key of “The Fifth”. The title referred to Beethoven’s answer to his question: “It must be”.

Listener Crossword No 238 (October 3, 1934) was headed by a single stave of music (from Beethoven’s Op 135), with the inscription “Muss es sein? Es muss sein! Es muss sein!”

### Clue explanations

Conventions: * = anagram, < = reversal

No Misprint/Morse Count of 5 Answer Explanation
Across
1 ten(D)er   WEAK SPOT WE + ASK * + POT
8 c(O)ver   DRAPE RAPE after D
13 Ho(T)els   INNS N(ot) in INS.
14 m(O)th   LIVE-BOX EVIL < + B + OX
15 ma(N)   STATUA SA about TATU
16 grav(E)   INEARTH IN [fashionable] + EAR + T + H
19 eight(S)   OARY (YR + O) < about (monoplegi)A
20 ch(I)nk   RIME Two definitions
22 bu(S)hels   HOMER HOME [in] + R
23 b(A)ttle   FONE F + ONE
24 spoo(N)-shaped   CURET CURE + T’
26 vi(D)eo   TAPE RECORDING (ECO + (bi)RD) in TAPERING
31 (C)lapped   NAPOO NAP + OO
34 Pou(R)   TEEM M after TEE
36 Gr(O)tty   TACKY (s)TACKY(ard); sard = silica
38 (S)ly   ARCH CATHEDRAL IS * – DETAILS *
39 (S)tem   EDDO E(vening) + ’D + DO
43 chican(O)   NORTEÑO (R(ace) + T(ake) + E(njoyment)) in NO-NO
44 ma(N)   ANYONE (NY + ON) in AE
45 l(E)af-cutter   ERGATES GREATES(t) *
46 Pre(S)ence   MIEN I in MEN [chess]
47 (T)ime   DIOTA D(ecompose) + IOTA
48 tart(S)   DESSERTS STRESSED <
Down
1 mag(I)   WISDOM WIS + MOD <
2 bo(D)s   ENTIA IN TEA *
3 see(D)   ANATROPY A + N(erve) + ATROPHY – H
4 fog(Y)   SQUARE QU in (SAR + E)
5 TT → –– = M clou(D)y PHAEIC PHASE – S + I + C [cloudy]
6 IIT → ••– = U flay(I)ng OLIO FOLIO – F
7 III → ••• = S anor(A)k TINNER TIN + NER(d)
9 T → – = T drea(M) READ DREA(m) *
10 II → •• = I expr(E)sses ABRAM ABRAHAM – AH
11 T → – = T depo(T) POTHEEN Hidden
12 TIII → –••• = B powe(R)ful EXHORT EX + R in HOT
18 h(U)nger   PYNE Hidden
21 (M)ould   MUCOR MOR about UC [upper case]
25 (P)errier   PIED NOIR PIED + I in NOR
27 grea(T)er   A MAJORI A + J in MAORI
28 (Y)ears   RAYNE Y in RANEE – E
29 TT → –– = M Fran(C)h DEED DE + DE <
30 IIT → ••– = U cann(E)d STONED Two definitions
32 III → ••• = S inde(X) PAINED (PAY INDEX – Y – X) *
33 III → ••• = S unlo(C)king OCTANS OCTANES – E
34 I → – = E neig(H)bour THINKS THIN + KS; reference Kansas, Oklahoma = OK
35 III → ••• = S embr(A)cing DOZENS D’ + OS about ZEN
37 III → ••• = S adva(N)ce CARGO CAR + GO
40 I → – = E usin(G) DONET D + ON + ET
41 II → •• = I valu(E)less ÉTAT E + TAT
42 TI → –• = N drug(S) DOSE DOES *