The most common and most likely answer to this crossword clue is the 7 letter word UNISONS
U
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I
S
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Buddy explains!
The straight part
We know that "concerts" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case concerts = unisons.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 UNISONS mean?
UNISONS noun- (acoustics) Identical pitch between two notes or sounds; the simultaneous playing of notes of identical pitch (or separated by one or more octaves).
- (acoustics) A sound or note having the same pitch as another, especially when used as the base note for an interval; a unison string.
- The state of being in harmony or agreement; harmonious agreement or togetherness, synchronisation.