Bands with a secondary lead vocalist that shows up on plenty of album cuts, but never the singles

Not a single, though.

Also "Roll Over Beethoven."

"Something" is an odd one, the first Beatles single to be taken from an aleady-released LP, with quite a few more to follow through the 70s. They hadn't officially broken up when it was released, but had already played together for the last time. It counts as a canonical Beatles single, it just doesn't feel like it does.

One of those triv questions: "The last Beatles single to reach Number One in the UK"

Not a single, though.

Bikini Kill seems like a great pick. At a smaller scale I believe this is also true of Le Tigre, where Johanna Fateman (and I believe JD Samson?) had several prominent album tracks, but none of their singles or legacy songs.

Ringo sings on every Beatles album (right?) but he wasn't on a UK single till '78.

"Yellow Submarine" was earlier than that!

ffs yellow submarine

Yeah, I thought Ringo had had a single BEFORE George with "YS" which would have been pretty hard for George (until I found out about "DYWTKAS") !

UK albums Ringo doesn't sing on: A Hard Day's Night, Magical Mystery Tour and Let It Be.

Although MMT wasn't really an album in the UK.

Brian (May) especially had lots of lead vocal cameo parts on his later singles ... as his ego is massive

Is this actually a known thing? I always had the impression that by comparison to most of his peers, May is relatively unassuming.

Jesus and Mary Chain?

Did William sing lead on "Darklands" and "Almost Gold"?

Yes

Both were singles. Telling ya, the singles thing is a tough nut to crack!