Theme: Right Out of the GATE. Anagrams.
18. Beverage from China's Wuyi Mountains : OOLONG TEA. The best tea I ever had was from a tea room in San Francisco's China Town - Oolong Formosa, selling for $30 an ounce. It tastes like caramel and butter. The complexity of teas from the highest peaks in Taiwan are becoming harder to come by as land is reclaimed to prevent erosion. Tragic.
3. Make terrific progress : GO GREAT GUNS
5. Protective vests, gas masks, etc. : RIOT GEAR
28. Rep seeking promising performers : TALENT AGENT
42. "Stop sweating the small stuff!" : GET A LIFE
60. Attend a party uninvited ... and a literal hint to five sets of circled letters : GATE CRASH.
Melissa here. "Crash" indicates the circled letters are scrambled. This was a little crunchy for a Tuesday - the circles helped fill in a few unknowns. Fun to see theme answers both across and down.
Across
1. Composer heard at graduations : ELGAR. Sir Edward Elgar composed Pomp and Circumstance, traditionally heard at graduation ceremonies.
6. Exerciser's target : FLAB
10. Rescue from trouble, with "out" : BAIL
14. Actress Watts of the "Divergent" films : NAOMI
15. Change the decor of : REDO
16. "... __ and for all!" : ONCE
17. Medical prefix with -plasty : ANGIO. Not rhino.
20. Insertion marks : CARETS
22. World's longest river : NILE
23. Accessory usually not worn on casual Fridays : TIE
24. Bearded antelope : GNU
26. Cast a spell on : BEWITCH
31. From time immemorial : AGE OLD
34. Eritrea's capital : ASMARA. Oh sure, I knew that. In the Horn of Africa, east of Sudan, and just west of the Red Sea.
35. Opel model meaning "stars" in Latin : ASTRA
37. Ears in the field : CORN
39. Move wearily : PLOD
40. On-call doctor's gadget : PAGER. Still?
41. Flightless Aussie bird : EMU
42. Ballpark figure : GUESS. Love this clue.
43. Lie adjacent to : ABUT
44. Small songbird : WREN. Did you know wrens can be colorful? Above is a variegated fairy-wren, and at left is a purple crowned wren.
45. German artist Max : ERNST. (2 April 1891 – 1 April 1976) Painter, sculptor, graphic artist, poet.
46. Movie theater : CINEMA
48. Six-line sonnet section : SESTET
50. Subjugate : ENSLAVE
52. Salty expanse : SEA
53. Nav. VIP : ADM
56. Drought-stricken : SERE. What? Is this Tuesday?
58. Torment : PLAGUE
65. Passport, e.g.: Abbr. : IDENT. Not GovID.
66. Like a thesis defense : ORAL
67. James of jazz : ETTA. A Sunday kind of love 💘.
68. Backyard border : FENCE
69. Flamingo color : PINK
70. Unhappy fate : DOOM
71. Fragrant compound : ESTER
Down
1. Make official, as a law : ENACT
2. Hawaiian island, or Hawaiian porch : LANAI
4. French sweetie : AMIE
6. To and __ : FRO
7. Novelist Uris : LEON. Known for his historical fiction novels.
8. Improvise on stage : AD LIB
9. Algebra type : BOOLEAN
10. Marsh : BOG
11. Pantry pest : ANT
12. Cubes in a tray : ICE
13. Grassy field : LEA
19. The first "N" of CNN : NEWS. Cable News Network.
21. __-cone : SNO
25. Stomach woe : ULCER
27. Contaminated : IMPURE. Sneaky, I was looking for a verb.
29. White symbol on Switzerland's flag : CROSS
30. Owned, old-style : HADST
32. Storybook sister who pushed the hag into the oven : GRETEL
33. Semicircular roofs : DOMES
35. Speedily : APACE
36. Polio vaccine developer : SABIN
38. Mystical letters : RUNES
44. Was indecisive : WAVERED
47. Opposite of fem. : MASC
49. Autumnal equinox mo. : SEP
51. Muse for poets : ERATO
54. Nincompoop : DUNCE
55. Taxi calculator : METER
57. This, in Spain : ESTO
59. Summer refreshers : ADES
60. Republican org. : GOP
61. Shapiro of NPR : ARI
62. Shade provided by the sun? : TAN. Great clue.
63. Moose kin : ELK
64. Popular Easter entrée : HAM