The most common and most likely answer to this crossword clue is the 5 plus 7 letter word OPERA COMIQUE
I've seen this crossword clue in The Guardian
O
P
E
R
A
C
O
M
I
Q
U
E
Buddy explains!
The straight part
We know that "Tom Jones?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case tom jones? = opera comique.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.