At Metric, Waronker pitched songs to Dick Glasser at Warner Bros. and Jimmy Bowen at Reprise. Impressed by his song demos, Bowen and Glasser recommended Waronker to Reprise label president Mo Ostin. Ostin subsequently hired him as a junior A&R representative for Reprise and for Warner Bros., which was then run by Joe Smith. Charged with developing artists who were originally on the roster of Autumn Records, a defunct label Reprise had acquired, Waronker produced the Mojo Men's "Sit Down, I Think I Love You," hiring Newman on piano and Van Dyke Parks as an arranger. He also produced Harpers Bizarre's "The 59th Street Bridge Song (Feelin' Groovy)," which he hired Leon Russell to arrange. Both songs were hits.