What does the cryptic crossword clue "An unreal performance by Strummer? (3,6)" mean?

The definition is "An unreal performance by Strummer?". The wordplay uses a cryptic definition. Cryptic definition The answer is AIR GUITAR.

An unreal performance by Strummer? (3,6)

Times Cryptic #29081 | 9 Across | 2024-11-22 flower