I soak up musical on its return, again and again (9)
I believe the answer is:
iterative
'again and again' is the definition.
'i soak up musical on its return' is the wordplay.
'soak' becomes 'ret' (ret can mean to soak in water).
'up' says the letters should be written backwards (in down clue: letters go upwards).
'musical' becomes 'evita' (I've seen this before**).
'on its return' says the letters should be written backwards.
'ret' written backwards gives 'ter'.
'evita' in reverse letter order is 'ative'.
'i'+'ter'+'ative'='ITERATIVE'
(Other definitions for iterative that I've seen before include "bears repeating" , "Relating to repetition" , "repeated" , "Involving repetition" .)