Slowly advanced to the ring (5)
I believe the answer is:
lento
'slowly' is the definition.
(musical instruction)
'advanced to the ring' is the wordplay.
'advanced' becomes 'lent' (advance can mean to lend).
'to the ring' becomes 'o' (letter resembling a ring).
'lent'+'o'='LENTO'
(Other definitions for lento that I've seen before include "How one scores slowly" , "Slowly (mus.)" , "Slow musically" , "Slow (music)" , "(When playing music) slowly" .)