From Charles Montpetit:

And since you asked, here’s how your non-musical, non-thematic clues could have gained a melodic angle (I’m not saying that the following ideas are better than yours, I’m just answering your request):

5a (CAMO): Rihanna outfit inspired by 65-Down

15a (ORAL): Type of tradition steeped in ballads, songs and chants

17a (IN DIAPERS): How Lady Gaga admittedly hosted SNL (because she “was laughing so hard”)

19a (NITTI): “Ghettoville USA” rapper named after a Chicago gangster

20a (ODELL): Award-winning director Jonas, of Rolling Stones, U2 and Franz Ferdinand videos

21a (AGERS): Stereotypically, if they’re golden, they’re into Perry Como

23a (SOD): The old one is associated with Irish folk music

24a (MERLIN): Character in Rick Wakeman’s “The Myths and Legends of King Arthur and the Knights of the Round Table”

28a (BERN): Site of Das Strassenmusik-Festival

38a (STENO): Type of pool in Frank Zappa’s “Greggery Peccary”

39a (ODOR): Public Enemy’s “New Whirl ___” (a conspiracy theory pun)

46a (EVIL OTTO): Berzerk character whose line “Intruder Alert” made it to #1 on the UK dance chart

48a (SLATER): Actor Christian, whose Broadway debut was in “The Music Man”

50a (FARO): Gluck’s Orfeo aria “Che ___”

61a (LIE ON): Dave Matthews Band song “___ Our Graves”

63a (PAINE): Pioneering American composer John Knowles

64a (IMAGE): It’s both Public and Limited in punk music

66a (PROVENCAL): Fife-and-drum style of folk music, in southern France

68a (SONIC): Youth in alt-rock

69a (OTRA): Il Divo’s “Solo ___ Vez”

a 72a (TSAR): Russian anthem “God Save the ___”

1d (IDIOM): Face the music, say

3d (UNDER): Word before “Pressure” (or “My Thumb”)

4d (STILL): Song title for the Commodores, the Foo Fighters, Alanis Morissette and Macy Gray

5d and 40a (COP A PLEA): Big Sugar advice to those who want to get off easy

6d (AREA): Douglas Adams fictional band Disaster ___

8d (OLSEN): Twins with the albums “I Am the Cute One,” “Brother for Sale” and “Cool Yule”

9d (TONSILS): R. Kelly had them surgically removed last year (and wrote a song about it, too)

10d (HOI): Todd Rundgren’s “___ Polloi”

11d (EMTS): David Lee Roth began training as one of them in 2004 (really)

18d (ALIBI): America album which could get you off

22d (RDA): Rheostatics song (or vitamin dosage acronym)

27d (ALTHO): “___ it’s been said many times, many ways…” (The Christmas Song)

29d (RIP): Copy a CD

31d (DEUT): Bk. of the Bible which features the Song of Moses

32d (A NET): Grateful Dead album “Without ___”

34d (VOWS): Kimbra album which debuted at #14 on the Billboard 200 in 2012

36d (ROMA): Nino Rota did its soundtrack for Federico Fellini

37d (GRATE): What a whippersnapper’s music does to an old fogey’s ears

42d (AIRS): What divas put on, or interpret

45d (NEGLECT): “A Night of ___” (Glee musical about under-appreciation)

47d (LOUPE): B.B. King’s “C’est ___” (literally, “It’s missed”)

49d (RBI): One of 80 for outfielder and Grammy-nominated guitarist Bernie Williams

52d (DEPOT): Twice, a Tom Waits song (or a Tom Petty title Street)

55d (MICAH): Nylons baritone Barnes, named after an Old Testament Prophet

56d (EN AMI): “As a friend,” to Céline Dion

57d (RELIC): Fender guitar model commissioned by Keith Richards (or Richards himself, to some)

58d (DISC): It can be compact or picture

52d (NORA): Broadway musical whodunit “Nick & ___”

60d (NANU): Half a old catchphrase for the voice of Lovelace and Ramon in the “Happy Feet” movies

65d (GIS): They sing “Sound Off,” “Blood on the Risers” and various jody calls

67d (VAR): The spelling “Aleksandr Borodin,” for instance (abbr.)

Don’t worry, I won’t do this each time. I just wanted to see whether it could be achieved.