Lack of interest in a track by Yes (6)
I believe the answer is:
apathy
'lack of interest' is the definition.
'a track by yes' is the wordplay.
'track' becomes 'path' ('path' can be a synonym of 'track'**).
'by' says to put letters next to each other.
'yes' becomes 'y'.
'a'+'path'+'y'='APATHY'
'in' acts as a link.
(Other definitions for apathy that I've seen before include "Indifferent quality" , "Complete lack of interest, indifference" , "Indifference, emotionlessness" , "State of listlessness or disinterest" , "Unconcern" .)