Line on a karaoke screen (5)
I believe the answer is:
lyric
'line on a karaoke screen' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for lyric that I've seen before include "Of poetry that expresses the poet's feelings" , "One barred from native country" , "Expressing personal feelings" , "Expressing poetical emotions" , "Cyril (anag.)" .)