Experimental musical brought back behind shelter (9)
I believe the answer is:
tentative
'experimental' is the definition.
(tentative can mean experimental or exploratory)
'musical brought back behind shelter' is the wordplay.
'musical' becomes 'evita' (Andrew Lloyd Webber musical).
'brought back' is a reversal indicator.
'behind' means one lot of letters go next to another.
'shelter' becomes 'tent' (canvas shelter).
'evita' written backwards gives 'ative'.
'ative' put after 'tent' is 'TENTATIVE'.
(Other definitions for tentative that I've seen before include "Diffident" , "Cautious - provisional" , "Exploratory - hesitant" , "Conjectural" , "Exploratory, unconfident" .)