Rajkumar trained in classical music when he was with Gubbi Veeranna's theatre troupe. The track "Om Namaha Shivaya" from the 1956 film "Ohileshwara", that he also starred in, was his first song for a film. He subsequently sang "Thumbithu Manava", a duet with S. Janaki, for the movie "Mahishasura Mardini" (1959). However, he became a full-fledged singer only in 1974 when he sang in place of P. B. Sreenivas for "Sampathige Savaal", who had till then sung for most songs picturised on Rajkumar, fell ill. Rajkumar sang the energetic "Yaare Koogadali" for the film which became widely popular during the time and is considered one of his best songs.