John began writing music at the age of 12. His first band, Family Crisis, played shows with 7 Seconds and Bad Religion.

In 1994 he formed Goldfinger as lead singer, songwriter, producer, and mixer. Known for dynamic live performances, Goldfinger played 385 shows in 1996 alone. Goldfinger has sold 4 million albums worldwide.

During his time as an A&R for Red Bull, Maverick & Warner Bros. Records, Feldmann signed The Used, D.R.U.G.S, Goldfinger, Showoff, City Sleeps, Story of the Year, Foxy Shazam, Mest, Itch, Blitz Kids and Beartooth. John is currently A&R for BMG.

John has also done production work/songwriting for The Cab, The Veronicas, Krewella, All Time Low, Sleeping With Sirens, Sweet Suspense. Avicii, Good Charlotte, Mest, The Used, Story of the Year, Ashlee Simpson, One Ok Rock, Hilary Duff, Goldfinger, Showoff, The Matches, Atreyu, City Sleeps, Anthony Green, Oh Honey, Beat Union, Cute Is What We Aim For, Escape the Fate, Get Scared, After Midnight Project, Foxy Shazam, Allstar Weekend, Panic! at the Disco, Boys Like Girls, Megan Joy, Jessica Lowndes, Plain White T's, 5 Seconds of Summer, Mandy Moore and Kelis among others.

John is always looking for new artists, songwriters, and producers to collaborate with and is passionate about making great music.