Variety act ends with melody (7)
I believe the answer is:
descant
'melody' is the definition.
(I have seen 'Upper melody ' mean 'descant' so perhaps 'melody' could also mean 'descant')
'variety act ends' is the wordplay.
'variety' indicates an anagram.
'act'+'ends'='actends'
'actends' is an anagram of 'DESCANT'.
'with' is the link.
(Other definitions for descant that I've seen before include "Sung variation" , "Treble melody above the main melody" , "Highest range (eg of a 10)" , "Ornamental melody added above a theme" , "Independent melody sung above a basic melody" .)