Question: Harish Raghavendra is an example of what term for a singer whose singing is pre-recorded for use in movies? 
Sentence (from "See the USA in Your Chevrolet"): In Your Chevrolet" (title as filed for 1950 copyright) is a commercial jingle from c. 1949, with lyrics and music by Leo Corday (ASCAP) and Leon Carr (ASCAP), written for the Chevrolet Division of General Motors.
Relevant evidence: No