SIGHT-SINGING ANSWER:
Fugue in C-minor from the Well-Tempered Clavier, Book 1. (J.S. Bach)

Across 
1- Editor’s mark STET
5- Humid DAMP
9- It’s shaped like an F on basses HOLE
13- Pakistani talk URDU
14- Hold back DETER
15- Negative situation DRAG
16- Silver strap? REIN
17- With disdain ICILY
18- “Let the cymbal ____” RING
19- Think the world of ESTEEM
21- Architect I.M. PEI
22- E.B. White, to his friends ANDY
23- ____ du Lac, WI FOND
25- OK town ENID
27- Letterman Corp. “Worldwide ________” TROUSERS
31- Formerly Danzig GDANSK
35- Castro brother RAUL
36- Without SANS
38- Declaim ORATE
39- Polo Grounds legend OTT
40- Smokeless tobacco brand SKOAL
42- Neighbor of Wash. ORE
43- Traffic jam TIEUP
46- Sea eagle ERNE
47- Yemen neighbor OMAN
48- Large wasp HORNET
50- Exhaust outlet TAILPIPE
52- Culture medium AGAR
54- On the main ASEA
55- Plays a wrong note ERRS
58- Like a 2009 car NEW
60- Trumpet fanfare TUCKET
64- Old photo mag LOOK
65- Nehi flavor GRAPE
67- Memo heading INRE
68- Grease job LUBE
69- Tennis great Rod LAVER
70- Evocation of sentimental music TEAR
71- Feeder fare SEED
72- Popular Irish singer ENYA
73- Abominable English rock band? YETI

Down 
1- Deodorant brand SURE
2- Very, in Versailles TRES
3- Prepare tapes EDIT
4- Melodious TUNEFUL
5- Last mo. DEC
6- Take ___ from me ATIP
7- Fighting California pop quartet? MELEE
8- Nosy PRYING
9- High resolution scanner HDRADAR
10- Bassist O’Brien ORIN
11- Tenorman Harold LAND
12- Like omelets EGGY
14- Atmosphere of some clubs DIMNESS
20- Dawn goddess EOS
24- Park Ave. hotel, with “The” DRAKE
26- Altar words IDO
27- Plighted in 26 down. TROTH
28- Proportion partner RATIO
29- One who tells the secrets of others OUTER
30- Quick drink SNORT
32- Singer and model Campbell NAOMI
33- Sax holder STRAP
34- Site of NH music festival KEENE
37- Capital of Yemen SANAA
41- Fish spear LEISTER
44- Like much advice (for) UNASKED
45- Tuning device PEG
47- Lack of transparency OPACITY
49- What amp cords often do TANGLE
51- Monetary unit of Romania LEU
53- Showed again RERAN
55- Old cloth measures ELLS
56- Libertine ROUE
57- Chorister’s garb ROBE
59- Woodstock clown ____ Gravy WAVY
61- Banjo locale KNEE
62- Quod ___ demonstrandum ERAT
63- Jazz singer Roiger TERI
66- Moving part in a whistle PEA