Sending up musical traveller on island is out of order (11)
I believe the answer is:
Here is my best explanation:
'out of order' is the definition.
'sending up musical traveller on island' is the subsidiary indication.
'sending up' is a reversal indicator.
'musical' becomes 'evita' (I've seen this before).
'traveller' becomes 'rep'.
'island' becomes 'i'.
'evitareponi' written backwards gives 'inoperative'.
'is' is the link.
(Other definitions for inoperative that I've seen before include "with no effect", "It's useless", "Anna -, Russian poet (Requiem)" and "Not in working order".)