Theme: No Kidding - Four leaders you should follow or else.
16A. *Comforter-and-sheets set for a large mattress, say : KING-SIZE BEDDING
22A. *Gaga way to be in love : HEAD OVER HEELS
36A. *Big tourist draw : MAJOR ATTRACTION
50A. *Industry-spanning work stoppage : GENERAL STRIKE
59A. Simon Says relative, and a hint to what happens after the starts of 16-, 22-, 36- and 50-Across : FOLLOW THE LEADER. "Mother, May I?" is in the same family.
Argyle here. While the theme doesn't do much for me, the three grid spanners on a Monday is impressive. The fill is consistent, user-friendly. All and all, a pleasant start to, for some, an unpleasant day.
1. Wynonna or Naomi of country music : JUDD. Country music's mother and daughter duo. Mama He's Crazy(3:08)
5. "Doctor Zhivago" heroine : LARA. Many versions! This is an instrumental. Lara's Theme(3:32)
9. Files opened with Adobe, for short : PDFS. (Portable Document Format)
13. Licked cookie : OREO. Ho! Ho! Ho!
14. Underage person : MINOR
15. La Scala showstopper : ARIA
19. Enter gingerly : EASE IN
20. Bigfoot cousin : YETI
21. "__ Misérables" : LES
25. Follow one's new job, in Realtorese : RELO. Realtorese? Really?
26. "Cheerio!" : "TA TA!"
27. Sci-fi vehicle: Abbr. : UFO
30. Attention from Dr. Mom : TLC
32. Answers an invite, for short : RSVP's. You notice; three ways to clue an abbreviation.
41. Movie trailer, e.g. : PROMO. Not an abbr. so much as a shortened word.
42. Sun, in Spain : SOL
43. Sea shocker : EEL
44. Hieroglyphic snakes : ASPS
47. Lovers' spat, say : TIFF
55. Right-angle piece : ELL
56. Pamplona runner : TORO. Have you seen the ad where the hook is "Now the bulls run from US!"
57. Professor's security : TENURE
62. Shade provider : TREE. In another month, maybe.
63. In __: mad : A RAGE
64. Not right in the head : LOCO
65. "Auld Lang __" : SYNE
66. Nevada gambling city : RENO
67. Auto repair figs. : ESTS. (estimates)
1. Comic's delivery : JOKE
2. Dickens villain Heep : URIAH
3. Like a thicket : DENSE
4. Folded corner : DOG-EAR. A way to mark your page and a bane to librarians everywhere.
5. Tina's "30 Rock" role : LIZ
6. "... for __, a tooth ..." : AN EYE. Old school, Old Testament.
7. Poet Frost : ROBERT. My kind of poet.
8. Franklin of soul : ARETHA. My kind of soul singer.
9. Hippie's digs : PAD. My kind of living quarters.
10. Dentist's tool : DRILL. Not kind.
11. Traffic violation consequences : FINES. Not kind, either.
12. Slumps : SAGS. See 5_Down.
14. Camera maker that merged with Konica : MINOLTA
17. Fries, for one : SIDE
18. Coke Zero competitor : DIET RC
23. Battery unit : VOLT. Standard automotive battery is 12 volts.
24. Sunup point : EAST
27. Baseball official : UMP
28. Gary Larson's "The __ Side" : FAR. Oh, how I miss it.
29. Pedro's peeper : OJO. I knew better but stuck in ORB anyway. D'oh!
31. Dol. parts : CT's. $ and ¢
33. Compete : VIE
34. "The Raven" poet : POE
35. NBC sketch show : SNL
37. Yemen neighbor : OMAN
38. Met, as a difficult challenge : ROSE TO
39. Decays : ROTS
40. Somewhat : A LITTLE
45. Like political hawks : PRO-WAR
46. "Hell is other people" French dramatist : SARTRE. (two R's, two R's)
48. At no charge : FREE
49. Big operatic ending : FINALE
50. Morning __: flower : GLORY
51. DeGeneres's sitcom : ELLEN. Only her talk show now, right?
52. Actress Lindsay : LOHAN
53. Praise : KUDOS
54. Straight up : ERECT
55. Young newts : EFTS
58. Greek Cupid : EROS
60. Golfer Trevino : LEE. I get a kick out of this ad.
61. Self-importance : EGO