Ones backing the artist - a girl from Barcelona (6)
I believe the answer is:
senora
'a girl from barcelona' is the definition.
I can't tell whether this defines the answer.
'ones backing the artist' is the wordplay.
'backing' says the letters should be written backwards.
'the artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'ones' in reverse letter order is 'seno'.
'seno'+'ra'='SENORA'
Can you help me to learn more?
(Other definitions for senora that I've seen before include "Lady of Spain" , "Mrs or madam (Spanish)" , "Lady overseas" , "Reason with a Spanish woman, probably married" , "Spanish lady within reason" .)