The most common and most likely answer to this crossword clue is the 11 letter word ONE-NIGHTER
I've seen this crossword clue in The Guardian
O
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Buddy explains!
The straight part
We know that "single performance" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case single performance = one-nighter.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 ONE-NIGHTER mean?
ONE-NIGHTER noun- An occasion when a performer or team of them (especially in vaudeville) expects to perform at a theater for a single evening.
- A single sexual encounter between two individuals, where at least one of the partners has no immediate intention or expectation of establishing a longer-term sexual or romantic relationship. As the phrase implies, the relationship lasts for only one night.
- Either of the two partners involved in such a single sexual encounter.