There's a lot to admire in this audacious debut. As a classical music lover and former cellist, I loved the notion of "classical composers sounded out with single words." Here they are, in case you didn't bother to search for the individual elements:

ROWE + SCENE + KNEE = Rossini
PACK + ELLE + BELL = Pachelbel
SHOW + PAN = Chopin
BATE + HOE + VENN = Beethoven
Notice how all the pronunciations are pretty darn good. I didn't like Pachelbel at first, but I think I've been pronouncing his name wrong all these years — apparently, it is "Pack-el-bel," not "Pahk-el-bel." (Or maybe I'm too much of a joon pahk fan.)
Also, it's very cool that Keiran used almost all normal words. The only oddball was BATE. (I love Mike ROWE and "Dirty Jobs.") If only he'd found a way to work in BAIT, it would have been a perfect set.
Speaking of working things in, working in 11 extra pieces of theme? That's insane. I would have told him that it couldn't be done cleanly. I was wrong, as the fill is amazingly smooth for the level of difficulty. ABED, CIRC, DELE, HWY is about as much crossword glue as any other Wednesday puzzle, but the theme is MUCH harder to execute on than average.
As much as I appreciated the puzzle as a constructor, I didn't particularly enjoy the solving process. When Keiran showed me the concept way back when, I didn't bother to look up the individual words; felt like too much work. Same happened during my solve.
It's a shame that some people will piece together BARBER OF SEVILLE from the crossings, and not bother to find the playful homophones making up "Rossini."
I wonder if it would have been more enjoyable if the clue for BARBER OF SEVILLE had been [Composition by cigarette purchase + Vogue rival + Old AT&T symbol?]?
But overall, it's a rare debut that makes me think so much and probe my feelings. Looking forward to more from Keiran.