Musical group attempt to tour America (7)
I believe the answer is:
chicago
'musical' is the definition.
(American musical)
'group attempt to tour america' is the wordplay.
'group' becomes 'Chic' (musical group).
'attempt' becomes 'go' (go is a kind of attempt).
'to tour' is an insertion indicator (to tour can mean to go around).
'america' becomes 'a' (common abbreviation - e.g. in organisation names).
'chic'+'go'='chicgo'
'chicgo' placed around 'a' is 'CHICAGO'.
(Other definitions for chicago that I've seen before include "America's Windy City" , "Musical (in Illinois?)" , "1970s' John Kander/Fred Ebb musical" , "Illinois port" , "Port on Lake Michigan" .)