Comes through slowly and checks out the piano (5)
I believe the answer is:
seeps
'comes through slowly' is the definition.
I can't judge whether this definition defines the answer.
'checks out the piano' is the wordplay.
'checks' becomes 'sees' ('see' can be a synonym of 'check').
'out' means one lot of letters goes inside another.
'the piano' becomes 'p' (musical abbreviation).
'sees' enclosing 'p' is 'SEEPS'.
'and' is the link.
Can you help me to learn more?
(Other definitions for seeps that I've seen before include "Oozes" , "Leaks slowly" .)