Singers disturbed rector with his bit of skirt (10)

'singers' is the definition.
(chorister is a kind of singer)

'disturbed rector with his bit of skirt' is the wordplay.
'disturbed' indicates anagramming the letters.
'with' says to put letters next to each other.
'bit of' says to take the initial letters.
The initial letter of 'skirt' is 's'.
'rector' put after 'his' is 'hisrector'.
'hisrector' with letters rearranged gives 'chorister'.
'chorister'+'s'='CHORISTERS'