Top tune, two consecutive notes short (7)
I believe the answer is:
descant
'top tune' is the definition.
'descant' can be an answer for 'tune' (descant is a kind of tune). I'm not certain of the 'top' bit.
'two consecutive notes short' is the wordplay.
I cannot quite understand how this works, but
'notes' could be 'de' (two musical notes) and 'de' is present in the answer.
'short' could be 'scant' (synonyms) and 'scant' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for descant that I've seen before include "Treble melody above the main melody" , "Melody sung or played above a basic melody" , "Highest range (eg of a 10)" , "Ornamental melody added above a theme" , "Independent melody sung above a basic melody" .)