Don't you love it when a mistake actually helps? It's so rare, especially on a Saturday.
Let me just say, before I get into all that, that I love this grid shape, with the vague S shape, with two open chunks going across just above and below the middle. The trio of 15-letter answers down the middle is a nice challenge that is met beautifully by Mr. Last.
So I got entree at 5A: ____ of Glamis (Shakespearean epithet) (THANE). I didn't need the parenthetical to get this reference to the Scottish play. Off of the H, at 6D: Modern-day "You can't please everyone", I immediately put in HAshtaG... figuring I'd get the ironic completion later on. As you can see, although I was wrong, I was in fact correct in two of those 7 letters after the H. Actually, now that I think about it, my mistake really didn't help me that much.
Actually, I had to leave all that and work in the lower section of the grid to get further purchase. 42A: Book with the line "My father can read big words, too. / Like Constantinople and Timbuktu" (HOPONPOP) was great - I remember that line with glee; after all, I was reading it to my kids. DOCTRINAL and GUAPOS are very nice as well, and it was those entries that got me THENOTORIOUSBIG. When I had ____WNHR at the end of 18A: Night-life industry bigwig (CLUBOWNER), I realized my mistake above, and corrected 6D to the excellent HATERSGONNAHATE.
Meanwhile, there is a ton of excellent fill elsewhere, including YOYOMA, BOLLYWOOD, PACKERS, and IDONTBITE. That last one I had a W in the place of the D which made the SW the final section to drop: I had _IOWE at 45D: Current path? (DIODE).
The Cher reference is a nice rebuttal to the recent fooforaw over Wednesday's 71A: Exasperated comment from a feminist (MEN). This clue is far more interesting and non-offensive. Still, my favorite is definitely 30A, because I love the reinterpretation of "stretcher" from the sense of a medical transport bed to a person who is stretching. And, plus, well, you know. Yoga pants. Nuff said.
1A: Coddle (BABY) is pretty good. B. I didn't love PDS, OTO, or KYD. Otherwise, thumbs up all around for me.
How about that? Exact 40. HAMPSHIRE was a good bit of trivia. I put in tapas at 13A Option at una taqueria, which slowed me down a bit in the NW. I also tried sing instead of BLAB at 3D. There was enough that I knew (including the HOPONPOP reference, which I wrote in with confidence with no crosses since I read this book maybe 1,000 times to my kids) so that I had nice toeholds all over the grid. A few crosses were needed for ROSIESBAR, and, oddly, I had ___OMA at 4D and just couldn't figure out the musician's name until I corrected the BLAB error and figured out BABY (I agree with the B rating), then I remembered the YOYOMA performance, having watched the inauguration from a location in Concord, MA, which was mentioned in the new president's speech. I thought that 12D You might give them a ring (KEYS) was pretty good cluing.
I, too, had tried "tapas," and I had a few other guesses that didn't last, but overall this one went along pretty well. Well, except that I guessed HeGEL and SBe didn't look that bad, since SBA means little to me. Funny, because I worked for a small business, and then had my own, for about twenty-five years. Maybe I should have looked into getting a loan...
I needed quite a few crosses for HOPONPOP, having never read it to anyone, and I might have gone to a B+ for 1A, but other than that, I agree with all that has been written above. A solid Saturday.