The most common and most likely answer to this crossword clue is the 5 letter word RONDO
I've seen this crossword clue in Independent
R
O
N
D
O
More clues leading to the result RONDO
- Piece of music displayed in order on door
- Uncovered wrong note in musical piece
- Repetitive movement from knocker on door
- Piece of litter on doorstep
- King performing party piece
- Some music runs flat for Gershwin, for example, lacking intro
- Upset, and not to perform musical piece
- Start to record playing the same piece
- Johnny stripped after right piece of music
- Royal function involves performing music
Buddy explains!

The straight part
We know that "piece" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case piece = rondo.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 RONDO mean?
RONDO noun- A musical composition, commonly of a lively, cheerful character, in which the first strain recurs after each of the other strains.
- A small, disk-shaped piece of food, especially a single-serving dessert or small piece of candy.
- A dark-skinned grape, a hybrid of Vitis vinifera with Vitis amurensis and others.
- A game resembling keep-away, used to train soccer players: one group is tasked with completing a number of passes while the other group tries to take possession of the ball.
- A gambling game played with small balls on a table.