Theme: Circle the wagons!
17A. 1976 debut single for Heart : "CRAZY ON YOU"
27A. Stable warmer : HORSE BLANKET
37A. Nationality of the two leaders suggested by the starts of 17-, 27-, 43- and 57-Across : SIOUX
43A. Biding one's time : SITTING TIGHT
57A. Informal name for the double bass : BULL FIDDLE
Argyle here. Jerome has provided a nice companion piece to C.C.'s Monday puzzle. Center unifier and a couple of climbers to tie it together (but no grid spanners). It lends itself to a bunch of musical links which I am more than happy to provide.
Across:
1. Take off politely, as one's hat : DOFF
5. Small silvery fish : SMELT
10. Ogden's state : UTAH
14. "The African Queen" co-screenwriter : AGEE. James Agee shared the credit with none other than John Huston.
15. Apple drink : CIDER
16. Golfer Ballesteros : SEVE. Sadly, he died at the age of 54 in the same town he was born in, Pedreña, Cantabria, Spain.
19. Yoked bovines : OXEN
20. The Beatles' "And I Love __" : HER
21. Metal-yielding rocks : OREs. and 6D. Ones who dig 21-Across : MINERS
22. Practices in a ring : SPARS
23. 21-Across tester : ASSAYER
25. Chasing : AFTER
31. Hiding places in walls : SAFES
34. Wild pig : BOAR
35. "We __ the Champions" : ARE
36. Jack of old Westerns : ELAM. He had several "looks" so I'll link Google here.
39. Not left out of : IN ON
40. Pallid : WAN
41. Latvian capital : RIGA
42. Move with ease : COAST
48. Crime against one's country : TREASON
52. Follow : ENSUE
54. Carson's predecessor : PAAR
55. Mary's little lamb, perhaps : EWE
56. Cabernet containers : VATS
60. Correct copy : EDIT
61. Native Alaskan : INUIT
62. Got long in the tooth : AGED
63. A bit blue : RACY
64. Garb at the Forum : TOGAs
65. Raises, say : BETS
Down:
1. Russian cottage : DACHA. Tuesday and later in the week word.
2. Hideous giants : OGRES
3. Shaking causes : FEARS. First thought was for quakes.
4. Brimless cap : FEZ
5. Cricket official : SCORER. Does he do more than keep score?
7. Outshine fruit bars brand : EDY'S
8. Regulus's constellation : LEO. Sort of makes 22D. Regulus, for one : STAR a gimme.
9. __TV: "Not reality. Actuality." : TRU. If you care, the Wikipedia LINK.
10. Golf tournament first played in 1895 : U.S. OPEN. Odd there was no abbreviation indicator.
11. Portmanteau region between Dallas and Little Rock : TEXARKANA
12. Solemnly swear : AVER
13. Ones in a pecking order : HENS
18. They have strings attached : YOYOs
24. "Beg pardon ..." : "AHEM ..."
25. Leigh Hunt's "__ Ben Adhem" : ABOU. (may his tribe increase!) Poem LINK
26. Linen fiber source : FLAX
28. WWII torpedo craft : E BOAT. The German version of the PT boats.
29. Cupid's Greek counterpart : EROS
30. Portable shelter : TENT
31. Hems but doesn't haw? : SEWS. Cute.
32. Jai __ : ALAI
33. Hard to believe : FANTASTIC
37. Moral lapses : SINS
38. Punk star __ Pop : IGGY
39. Mite : IOTA
41. Marriage or baptism : RITE
42. Dearie, in Dijon : CHÉRI
44. Reliable : TRUSTY
45. Milano's land : ITALIA. Or Milan in Italy.
46. Botanists' scions : GRAFTS
49. Swamp grass : SEDGE
50. Young bird of prey : OWLET
51. Non-negotiable things : NEEDS
52. On any occasion : EVER
53. Zippo : NADA
54. Socket insert : PLUG. I jumped right on BALL. Wrong! So was bulb.
57. Bridle piece : BIT. Horse harness.
58. Half dos : UNO. Uno, Dos, Tres: One, Two, Three.
59. Gentle application : DAB
Argyle