Rocker taking lead in Chicago, the musical? (5)
I believe the answer is:
chair
'rocker' is the definition.
(thesaurus)
'lead in chicago the musical?' is the wordplay.
'lead in' suggests taking the first letters.
'the musical?' becomes 'hair' (1960s musical).
The initial letter of 'chicago' is 'c'.
'c'+'hair'='CHAIR'
'taking' is the link.
(Other definitions for chair that I've seen before include "Movable seat" , "What professor has" , "Academic position" , "Single seat" , "control meeting" .)