The most common and most likely answer to this crossword clue is the 7 plus 4 letter word WALKING BASS
W
A
L
K
I
N
G
B
A
S
S
Buddy explains!
The straight part
We know that "music to a cat’s ears" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case music to a cat’s ears = walking bass.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.