puzzle

 ACROSS

  1 Place to enjoy a mud mask

  4 Electrically flexible

  8 Ceiling

 11 Lead-in to "Major" or "Minor"

 13 Mild yellow cheese

 15 The "C" of TLC

 16 Op-ed piece, e.g. (note letter 15 in this clue's answer)

 19 Play matchmaker for

 20 "... but I could be wrong"

 21 One might take place in a conference room (letter 4)

 26 "Rubaiyat" poet Khayyam

 27 Relieved sounds

 28 O-shaped earring

 29 E or G, e.g.

 30 Hamster's home

 32 Fanatics

 34 Bothers incessantly (letter 1)

 36 Says "I am what I am!"

 40 Resistance units

 41 CEO's degree, sometimes

 44 Hilarious person

 45 Cavs, on a scoreboard

 46 Word before "ring" or "lighting"

 47 Very slim possibility (letter 3)

 52 "Luther" star Elba

 53 Home with a bird's-eye view

 54 Person in charge (letter 13)

 59 Pretentiously cultured

 60 Root beer-and-ice cream treat

 61 Celeste of "All About Eve"

 62 "For sure!"

 63 Legendary Himalayan beast

 64 Animated movie set in Brazil


DOWN

  1 The world revolves around it

  2 Suppose

  3 "In a manner of speaking ..."

  4 Visibly surprised

  5 "That's a ___-out!"

  6 Expected

  7 Disk drive inserts

  8 Word on yellow tape

  9 Pitcher's asset

 10 Writing tool for some crossword solvers

 12 Buzzing

 14 A lot, for some?

 15 Provide apparel for

 17 "German sausage jokes are just the wurst," e.g.

 18 Final number in "A Chorus Line," inaptly

 21 ___ choy

 22 It's a long story

 23 One helped raise Romulus and Remus

 24 Agree silently

 25 Apple Maps tech

 30 Cinematic FX

 31 Pantry pest

 32 Relatives, for short

 33 "___ not easy being green"

 35 Moisturizing butter type

 36 British singer Rita

 37 Drag queen's hairpiece

 38 "Don't give me any clues"

 39 Boring

 41 Keep an eye on

 42 Tenor Andrea

 43 Suffix for "Gator" or "Power"

 45 Not at all cheap

 46 Grassy wetland

 48 Letters seen outside a hit Broadway show

 49 Minor quarrel

 50 Desert plants

 51 "Isn't ___ bit like you and me?" ("Nowhere Man" lyric)

 54 Capital of Korea?

 55 Fury

 56 Groundbreaking tool?

 57 Enjoy some samosas

 58 Paramore genre

solution