Theme: Did you get the memo? - No? Look for it in these three theme entries.
20A. Residential loan : HOME MORTGAGE
35A. "I'd like to hear the rest" : "TELLME MORE"
42A. 1974 Jimmy Buffett song : "COME MONDAY"
56A. Office communication, and what can literally be found in 20-, 35- and 42-Across : INTERNAL MEMO
Argyle here. A theme reveal that could hardly be clearer. Gail and Bruce seem to be on a two week schedule, though today's isn't as complex as the last one. Straightforward, easy-peasey. Four nice long vertical entries. A musical flair today, also. Feel free to link your favorites.
Across:
1. Tip, as one's hat : DOFF. Word Origin & History - A contraction of do off, preserving the original sense of do as "put." At the time of Johnson's Dictionary [1755] the word was "obsolete, and rarely used except by rustics," but it was saved from extinction (along with don) by Sir Walter Scott.
Online Etymology Dictionary, © 2010 Douglas Harper
5. Empty spaces : GAPS
9. Subsides : WANES
14. Suffix with switch : EROO
15. Wilson of "Wedding Crashers" : OWEN. Owen Wilson and Vince Vaughn play a couple of rogues who mingle and tango at the receptions of weddings to which they weren't invited.
16. Texas shrine : ALAMO
17. Tall tale teller : LIAR
18. "Deck the Halls" syllables : FA LA la la, la la la.
19. Tear to shreds : RIP UP
23. About to happen : IN STORE. As in, "What's in store for us this week?" and 4D. Hint of the future : FORETASTE. As in, "Is this puzzle a foretaste of the coming week?"
24. Bronze from a day at the beach : TANNED. From one day? I doubt it.
28. René's friend : AMI
29. Appear to be : SEEM
31. __ Lingus: Irish carrier : AER
32. Russian fighter jets : MIGs. Strap yourself in a Mig. Link
38. Italian violin maker : AMATI. They say it's all in the varnish.
40. Squeak stopper : OIL. Is that what C.C. used to get rid of her mouse?
41. Rigs on the road : SEMIs. Tractor-trailers.
45. Reasons for extra innings : TIEs. Possible reason for the end of ties, 63A. Paths of pop-ups : ARCs. One more baseball reference: 29D. Base runner's option : SLIDE
46. "Tastes great!" : "YUM!". "Less filling!" : "Burp!"
47. Poet's inspiration : MUSE
48. Sow or cow : SHE
50. What social climbers seek : STATUS
52. Curtail : SHORTEN
59. Gangster John known as "The Teflon Don" : GOTTI. He died in a federal medical center, June, 2002, at the age of 61.
62. Twice-monthly tide : NEAP
64. Place on a pedestal : EXALT
65. Show some spunk : DARE
66. "That makes sense" : "I SEE"
67. Saunter : MOSEY
68. Vehicle on runners : SLED. NorthEast needed dog sleds.
69. Proof of ownership : DEED. 51D. Proof of ownership : TITLE
Down:
1. New __: India's capital : DELHI
2. Hunter constellation : ORION. Prominent in winter sky(Northern Hemisphere)
3. Heads on beers : FOAMS
5. "Take a shot!" : "GO FOR IT!". The result of too many 3D's?. 22D. "Lemme __!" : AT 'EM
6. Informed (of) : AWARE
7. Attack, as with snowballs : PELT
8. Stocking tear : SNAG
9. Military practice : WAR GAMES
10. Visitor from afar : ALIEN
11. Treat jet lag, perhaps : NAP
12. Earthbound Aussie bird : EMU
13. Dip, as bread in gravy : SOP. Shakshuka with a sop.
21. Dad's partner : MOM
25. Vocalist Judd : NAOMI
26. Really strange : EERIE
27. Bride's purchase : DRESS
30. Scat legend Fitzgerald : ELLA
32. Flagship store at New York City's Herald Square : MACY'S
33. Words from one with a bad hand : "I'M OUT". Think 'poker'.
34. Letter after beta : GAMMA
36. Long, long time : EONs
37. Parking ticket issuer : METER MAID
39. Resistance to disease : IMMUNITY
43. Expel : OUST
44. Like a slingshot handle : Y-SHAPED
49. Christmas, e.g.: Abbr. : HOL.. (Holiday)
52. Simple trap : SNARE
53. Far from talkative : TERSE
54. Intro giver : EMCEE. A lot of emcees on TV award shows this time of year.
55. Snooped (around) : NOSED
57. Pulls the plug on : ENDS
58. More than lifelike : REAL
59. Precious stone : GEM
60. Big name in kitchen gadgets : OXO. Reasonably priced.
61. Profs' helpers : TA's. (teaching assistant)
Argyle