Sing loads of rubbish and slide between notes (9)
I believe the answer is:
glissando
'slide between notes' is the definition.
(I've seen this before)
'sing loads of rubbish' is the wordplay.
'of rubbish' is an anagram indicator (I've seen 'rubbished' mean this).
'sing'+'loads'='singloads'
'singloads' is an anagram of 'GLISSANDO'.
'and' acts as a link.
(Other definitions for glissando that I've seen before include "Sliding effect in moving from one musical note to another" , "(Musically) a rapid series of ascending or descending notes" , "Musical flourish" , "Re-interpreting this musical direction" , "Slide between two notes" .)