Musical toy sis strewed all over the place (4,4,5)
I believe the answer is:
west side story
'musical' is the definition.
(I've seen this before)
'toy sis strewed all over the place' is the wordplay.
'all over the place' indicates an anagram.
'toy'+'sis'+'strewed'='toysisstrewed'
'toysisstrewed' with letters rearranged gives 'WEST SIDE STORY'.
(Other definitions for west side story that I've seen before include "New-York-gangs musical" , "Jets/Sharks musical" , "Musical from Shakespeare play" , "1957 musical set in New York City" , "Bernstein/Sondheim musical" .)