Just words in song T Rice composed with A Lloyd Webber’s musical backing (10)
I believe the answer is:
recitative
'just words in song' is the definition.
(opera singing style imitating ordinary speech)
't rice composed with a lloyd webber's musical backing' is the wordplay.
'composed' indicates an anagram.
'with' says to put letters next to each other.
'a lloyd webber's musical' becomes 'evita' (Andrew Lloyd Webber musical).
'backing' is a reversal indicator.
'evita' in reverse letter order is 'ative'.
't'+'rice'='trice'
'trice' with letters rearranged gives 'recit'.
'recit'+'ative'='RECITATIVE'
(Other definitions for recitative that I've seen before include "Sung speech, as in opera" , "tuneful speech" , "Operatic musical declamation" .)