Harish Raghavendra is an example of what term for a singer whose singing is pre-recorded for use in movies? 
Vikadan:  Playback singer Harish Raghavendra played the lead role, alongside Arun Pandian, gayathri raghuram, Radhika Chaudhari and Uma. Playback singer: A playback singer is a singer whose singing is pre-recorded for use in movies.
Playback singer