The most common and most likely answer to this crossword clue is the 8 letter word BACKBEAT
I've seen this crossword clue in The Daily Telegraph
B
A
C
K
B
E
A
T
More clues leading to the result BACKBEAT
Buddy explains!
The straight part
We know that "Something in a music bar" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case something in a music bar = backbeat.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.
What does BACKBEAT mean?
BACKBEAT noun- The sharp accent on the second and fourth beats of rock music in 4/4 time.