The most common and most likely answer to this crossword clue is the 10 letter word ACCORDIONS
I've seen this crossword clue in The Daily Telegraph
A
C
C
O
R
D
I
O
N
S
More clues leading to the result ACCORDIONS
Buddy explains!
The straight part
We know that "boxes, getting squeezed for notes" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case boxes, getting squeezed for notes = accordions.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 ACCORDIONS mean?
ACCORDIONS noun- A small, portable, keyed wind instrument, whose tones are generated by play of the wind from a squeezed bellows upon free metallic reeds.
- A vertical list of items that can be individually expanded and collapsed to reveal their contents.
- To fold up, in the manner of an accordion