Idols sang high for musical effect (9)
I believe the answer is:
glissando
'musical effect' is the definition.
(I've seen this before)
'idols sang high' is the wordplay.
'high' is an anagram indicator (can mean drunk or on drugs and hence disordered).
'idols'+'sang'='idolssang'
'idolssang' is an anagram of 'GLISSANDO'.
'for' acts as a link.
(Other definitions for glissando that I've seen before include "Sliding series of notes (mus.)" , "trombone slide, for example" , "note series rapidly executed" , "Note with sliding pitch" , "Musical flourish" .)