His first successful song as a writer was "She Say (Oom Dooby Doom)", a Top 20 chart-scoring song composed for the band The Diamonds in 1959. Mann co-wrote the song with Mike Anthony (Michael Logiudice). In 1961, Mann had his greatest success to that point with "I Love How You Love Me", written with Larry Kolber and a no. 5 scoring single for the band The Paris Sisters, (seven years later, Bobby Vinton's version would score in the Top 10). The same year, Mann himself reached the Top 40 as a performer with a novelty song co-written with Gerry Goffin, "Who Put the Bomp", which parodied the nonsense words of the then-popular doo-wop genre.