Everybody's favorite Thursday puzzle type - the rebus! And a multi-rebus at that. I knew there was something afoot at 17A: "Social media fad that went viral in 2014" because I couldn't get ICE[BUCK]ETCHALLENGE to fit. A little further along, however, I got [BILL]MAHER (TV host once with an "Explaining Jokes to Idiots" segment) and things started to make cents. Once I figured out that even though 'fur'OR might be a reasonable guess for "Ado" at 38A, 'fur'CHOWDER was a non-starter, I was able to throw in [CLAM] and get the rest of my ducats in a row. I had the most trouble with the northeast. I didn't know ANN Wilson, lead singer of Heart, and at first I couldn't make heads or tails of 10D: Part of a diner showcase, until PIE finally hit me in the face.
At first, after completing the grid, I was a little puzzled by the revealer FIVEDOLLARWORDS because the rebii seemed to be $1 words rather than $5 words, but when I mentioned it to Horace he explained that I had mis-parsed the answer. What seemed a little like a minor incongruity turned out to be perfect when understood as 'five (the quantity) dollar words' ([NOTE], [BUCK], [BILL], [SINGLE], [CLAM]). Ha! Now that's using your cabbage!
If I have one bone to pick, it's the cross between 21A: Jack of Rio Lobo" and 9D. "Tryst locale". I almost FWOED because I didn't know Mr. ELAM and I had entered [NOTE]LLhOTEL instead of the correct and excellent [NOTE]LLMOTEL]. D'oh!