Low part of track coming to round lake with fish (7,4)

'low part of track' is the definition.
The definition suggests a singular noun which matches the answer.

'coming to round lake with fish' is the wordplay.
'coming to' becomes 'waking' (I've seen this in another clue).
'round' means one lot of letters goes inside another.
'lake' becomes 'l' (geographical abbreviation).
'with' is a charade indicator (letters next to each other).
'fish' becomes 'bass' (bass is a kind of fish).
'waking' placed around 'l' is 'walking'.
'walking'+'bass'='WALKING BASS'

Can you help me to learn more?