You may not believe this, but my father recited the poem CASEYATTHEBAT (Poem subtitled "A Ballad of the Republic Sung in the Year 1888") at our family Zoom two weeks ago. We have been having these Zooms weekly for over a year now. Usually we just JABBER, but sometimes one of us gives a short presentation, or we play a game of Jeopardy together (each creating clues for one category), or we have a show and tell, but usually those events are announced. This time, after about twenty minutes, Dad just said "I'm going to read a poem this week." We were all familiar with the poem, because one of my brothers had recited it in high school many (many) years ago, but this recent reading certainly seemed somewhat out of the blue. Maybe it was just after opening day or something (yes, that must have been it, (No SOPHIST, I!)), but still.
So anyway, seeing it again today seemed quite strange. But really, it's only the first four letters we're concerned with here. They begin together, then shift one at a time to the right-hand side of the thematic entries. An interesting idea, and well done, as all five entries (with the possible exception of the poem) should appear quite common to most solvers.
I was surprised by both the clue and the entry on ASS-backwards. I thought the expression was "back-asswards," which is funnier, but maybe that construction was only possible once ASS-backwards had been established. I don't know. This is one case where I'm not going to dig into the etymology. I've typed it enough already!
Somebody loves "Pagliacci," huh? I got TONIO ("Pagliacci" baritone) entirely from crosses, but I was so sure of ARIA (without ever having heard of "Vesti la giubba") that I overruled "room" and corrected it to AREA (Floor plan info).
Anybody else notice that "robin" fits in where ARIES (Sign of spring) belongs? I did.