To play guitar on the street is unusual? (5)
I believe the answer is:
strum
'to play guitar' is the definition.
(I've seen this before)
'on the street is unusual?' is the wordplay.
'on' says to put letters next to each other.
'the street' becomes 'st'.
'is unusual?' becomes 'rum' (I've seen this before).
'st'+'rum' is 'STRUM'.
(Other definitions for strum that I've seen before include "Play stringed instrument with sweep of hand" , "Casually play (on a stringed instrument)" , "Play a banjo" , "Sweepingly sound guitar strings" , "Play idly on guitar etc" .)