Works for me

You were right: easy to guess but difficult to solve. I got the answer, but I have no idea what the intended mechanism was!

Fun to see a puzzle right in my wheelhouse like this! Still working on the backsolve — I'm confident I know the composers and works referenced in 1 and 66A, but now how to connect them to the answer...

Okay.... So the solution/backsolve

There are five numbered clues featuring music. The musical pieces are:

1)"Rigoletto" by Verdi 2)"Ring of the Nibelung" by Wagner 3)"Ode to Joy" by Beethoven 4)"The Pearl Fishers" by Bizet 5)"Madame Butterfly" by Puccini

You can verify the composers by 1A whose answer is VWBBP. And you could try to verify the works by 66A but you will find they do not fit as 66A is APFCT.

So we need a work by Verdi begining with A, by Wagner beginning with P, by Beethoven beginning with F, by Bizet beginning with C, and by Puccini beginning with T.

They are AIDA, PARSIFAL, FIDELIO, CARMEN, and TOSCA.

You can find those names hidden in five clues.

sAID A mouthful = On the nose

one who sPARS IF ALone = Pugilist

boneFIDE LIoness in "Born Free" = Elsa

CAR MEN = Racers

---- brody; winner of "the PianisT" OSCAr = Adrein

The initial answers of which spell out OPERA (which literally means "works")

... now....

Finding words in clues is dang near impossible. I hoped the odd wording of some of the clues wording of the clues would help. You might not know you were looking for AIDA or TOSCA (Verdi and Puccini were proficient) and if somehow it wasn't obvious we were probably looking for Operas FIDELIO may not have been obvious (it was Beethoven's only opera). But Bizet work beginning with C screams for CARMEN and then the clue right there is "Car Men" so... c'mon. Then the weird "spars if only"? Why "if alone" and why is the lioness "bonafide"? The Aida and Tosca are a bit more nature but wording "winner of 'the pianist' oscar"; shouldn't that be "'the pianist' oscar winner"? I deliberately reworded it to make it awkward.

Any way. I tried to leave hints as to the mechanism with clues 21D, 9D, and 13D which were otherwise awful clues and a reference to tessalations in 26D.

This whole thing was inspired by the WSJ contest this weekend which had the clue ""It happened one night" Oscar winner".

My original idea, which would have worked better would been to have symmetrical across entries: phoTO SCAm, boneFIDE LIon, he sAID A mouthful, sPARS IF ALone, osCAR MENu, and then have five other clues referring to the composers work. (For Beethoven's 6th I was thinking of "Creature featured in the Fantasia sequence of Symphony no. 6" or "Common name for the 6th Symphony" for P. Hence the image)

But filling in a grid with that many fixed long across clues and requiring five more fixed clues that have to be there was to much for me.

And that's the weird thing about crossword constructions. You make little concessions and quick fixes and you get too involved in the process you are creating to notice something damned near impossible to see ("What do you mean you didn't see 'Tosca' in '"It Happened One Night" Oscar winner'? It's right there!")

Anyhow... I don't know if it's telling that it was faster and easier create a meta than to solve the WSJ meta that inspired it.