Finnish producer and DJ Jussi Leväsalmi began making music after learning guitar as a teenager, and his earlier musical work included playing and writing for bands. Before focusing on 501, he made liquid drum & bass as Contour; as 501, he moved into dubstep, with his music also associated with drumstep. Leväsalmi has described his work more broadly as bass music. The name 501 came from a nickname he had as a teenager, inspired by Levi’s jeans. Based in Helsinki, he has also worked as a legal counsel alongside his music career.
His early singles include Mind Control / Hidden Worlds, released in 2009 on Offroad Recordings, and The 501 EP, released in 2010 on Not Safe For Work. In 2011, he put out the singles St. Ives / Can't Touch Me on Rwina Records, Strings Attached / Smoke And Mirrors on Untitled!, and Gist / Borderline on Subway Recordings. He also released the 12-inch The Eyes Never Lie / Downplay on Off Road Recordings and Dangerous / Special Request on Subway. His releases have appeared on Never Say Die Records, Off Road Recordings and Subway, and he has also issued remixes for Interscope and Skrillex’s OWSLA imprint.
In 2012, Headrush / Falling Skies, featuring Belle Humble, came out as a single on Never Say Die Records. The track “Headrush” reached number two on the Dubstep Beatport chart for four weeks in March that year. Leväsalmi later released the EP Infinity on Never Say Die Records, describing it as an attempt to give tracks sentiment and musical development beyond their drops. His other releases for the label include the EP Beat The System, while Crystallize was an EP made with RAS and Protohype. He has also remixed music for Far East Movement, Nelly Furtado and Fabio Landrum. Leväsalmi uses Reason to design synthesiser sounds and often rewires it to another DAW.