Eventually keeping rhythm (2,4)
I believe the answer is:
in time
'eventually' is the definition.
('in time' can be a synonym of 'eventually')
'keeping rhythm' is the wordplay.
'keeping' becomes 'in' (I can't justify this - if you can you should give a lot more credence to this answer).
'rhythm' becomes 'time' (time is a kind of rhythm).
'in'+'time'='IN TIME'
Can you help me to learn more?
(Other definitions for in time that I've seen before include "not too late" , "on schedule" , "Later perhaps" , "eventually" , "What musicians aim to be" .)