Theme. SURRENDER[S.] The second word of each two word theme fill is a synonym for capitulation. There's a flaw in the unifier though, as we shall soon see.
17. *"Rockin' the Suburbs" alt-rocker: BEN FOLDS. A person's proper name becomes a verb.
Moderately amusing, but Cf 33D
To FOLD is to capitulate.
24. *"Anything wrong?": WHAT GIVES? You OK? Inquiry into someone's general well being.
To GIVE [up or in] is to capitulate. A different sense of the verb GIVE.
36. *Not much interest: LOW YIELDS. Not much return on investment, like T-bonds and money markets these days.
To YIELD is to capitulate. The noun YIELD becomes a verb, just like magic!.
52. *Ursine dens: BEAR CAVES. Where they spend the winter.
To CAVE is to capitulate. Another noun to verb transition. Lots of grammatical alchemy going on here.
60. Concede ... or a hint to the last words of the answers to starred clues: CRY UNCLE.
Another way to capitulate.
But, you'll notice that the theme fill all end in "S," while the corresponding verb in the unifier does not. The latter represents the base form of the verb in present tense, as used in first and second person. The added "S" indicates third person. For example, I sleep and you sleep, vs he/she/it sleeps. This may be a niggling little quibble, but I find the inconsistency to be troubling, and am issuing a citation.
Hi gang. Jazzbumpa here, evidently in critical mode. Let's see what else gives. I will not capitulate!
Across:
4. Stark daughter on "Game of Thrones": ARYA. The deeply troubled middle child of Ned And Catelyn [Tulley] Stark. If you are familiar with her, no more explanation is needed. If not, neither of us has enough time. Read about her here.
8. "__ tardes": BUENAS. Good Afternoon in Madrid.
14. Kwik-E-Mart owner: APU. From The Simpsons
15. Spell the end of: DOOM. Seal the fate of.
16. "Bewitched" witch: ENDORA. Samantha's mother.
19. Periods of duty: STINTS. As defined.
20. 38th-parallel land: KOREA. Approximately the border between North and South Koreas.
21. Covered, as with sugar: COATED.
22. Novel makeup: PROSE. Not unusual cosmetics; instead, it's normal written language, as opposed to poetic verse.
27. Responsibility: ONUS. A duty or responsibility.
28. Aviation pioneer Sikorsky: IGOR. [1889 - 1972] Influential in the development of both helicopters and fixed wing aircraft.
29. Bottle part: NECK. Located just below the CAP.
30. Like many MLB players: LATINO. Many from the Dominican Republic.
32. Sun and Sky org.: WNBA. Chicago Sky and Connecticut Sun are teams in the Women's National Basketball Association.
35. Cowboy Rogers: ROY. Leonard Franklin Slye [1911-1998] was an American singer, actor, and television host. Following early work under his given name, first as co-founder of the Sons of the Pioneers and then acting, the rebranded Rogers then became one of the most popular Western stars of his era.
39. Do sum work: ADD. +1 for this nice word play.
42. Southwest art hub: TAOS. In New Mexico.
43. Low-tech travel guide: AAA MAP. Paper map from the American Automobile Association.
47. The "F" in UHF: Abbr.: FREQ. Frequency - the vibration rate of a wave. For Ultra High Frequency [UHF] the range is 300 MHz to 3 GHz.
49. "Not happenin'": UH-UH. Nope. No go.
51. YouTube vote: LIKE. Thumbs up. You could give one to Ben Folds. [I didn't]
55. Really cold: POLAR. Relating to the north and south poles, or weather patterns that come from those directions.
56. Riverdale High redhead: ARCHIE. From the comic books. Archie first appeared in Pep Comics #22 in 1941 and soon became the most popular character for the comic. Due to his popularity, he was given his own series which debuted in winter 1942 titled Archie Comics.
59. "All set here": I'M GOOD.
63. Epicure: FOODIE. One with a particular interest in food and its preparation
64. Actor Brad: PITT. William Bradley Pitt is an American actor and film producer. He has received multiple awards, including two Golden Globe Awards and an Academy Award for his acting, in addition to another Academy Award, another Golden Globe Award and a Primetime Emmy Award as a producer under his production company, Plan B Entertainment.
65. 62-Down homonym: AIR. They sound alike, and no mistake.
66. Astronomer Celsius: ANDERS. [1701-1744] He was a Swedish astronomer, physicist and mathematician.
67. Lemon drinks: -ADES. They are helpful in hot weather.
68. "Fresh Air" network: NPR. National Public Radio.
Down:
1. Semi driver's spot: CAB.
2. Impersonate: APE. Mimic.
3. Quit like a wimp: PUNK OUT. I'm not familiar with the phrase, but it's easy enough to suss
4. Love to bits: ADORE.
5. One played on stage: ROLE. By an actor
6. "'Sup, bro?": YO DAWG. Slangy greetings.
7. Alarm-setting hrs.: AMS. In the morning.
8. Make smitten: BESOT. Quaint ways of falling in love.
9. De-identify, as an Insta photo: UNTAG. Disassociate the picture from a name, as on FaceBook.
10. Add, as to text: EDIT IN.
11. "Ain't gonna happen": NO, NEVER. Dream on. Cf 40D.
12. Like many Miami Beach structures: ART DECO. Read about it here.
13. Airline to Sweden: SAS. Scandinavian Airlines System or legally Scandinavian Airlines System Denmark-Norway-Sweden.
21. __ asada: CARNE. Roasted meat at your local restaurante mexicano.
22. Campaign pro: POL. Politician.
23. Genetic letters: RNA. Ribo Nucleic Acid
25. "My guy doing okay, doc?": HOW IS HE. Inquiry into his physical or mental condition
26. What's up to you?: SKY. Where the stars are all aglow
28. Illinois neighbor: IOWA. Flyover country.
31. "That's __ fair!": NOT. Play nice, now.
33. Lackluster: BLAH. Meh!
34. Crest box abbr.: ADA. American Dental Association.
37. "__ been served": YOU'VE. What did I get?
38. Spot for a Wild West brawl: SALOON. Cliche scene.
39. Langley, e.g.: Abbr.: AFB. Air Force Base.
40. "Like that'll ever happen": DREAM ON.
44. Dairy container: MILK CAN.
45. Letters before a pen name: AKA. Or alias: Also Known As.
46. Each: PER.
48. Scanned black-and-white image: QR CODE. This thing.
53. Group with scores: CHOIR. Musical scores to sing from.
54. Senate staffers: AIDES.
55. Mopes: POUTS.
58. Data storage unit: BYTE. The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit of memory in many computer architectures.
59. "__ tree falls ... ": IF A. Yes, it makes a sound. Physics does not care where you are.
60. Tax pro: CPA. Certified Public Accountant.
61. Sassy reaction: LIP. Disrespectfully talking back.
62. Misspell a word, say: ERR. Any sort of mistake.