In the early '90s Mental Theo worked for Arcade Records as an A&R Manager and created several Techno, Dance & House compilations, and the biggest Hardcore compilation in the world ever, (Thunderdome), ID&T was in those days responsible for the first massive Hardcore events in The Netherlands. During this process Theo met Charly at a Mallorca reunion in Utrecht and they decided to work together on new music .Mental Theo promoted the tracks on the Thunderdome cds and together they started a label called Maximum Record. It took a year before they scored worldwide hits with their debut single, "Wonderful days" and sold millions of records. Eleven hit singles followed. ID&T continued the Thunderdome cd’s after Theo left Arcade and decided to work with Polydor & Motor music together with Charly Lownoise. DJ Charly Lownoise (born Ramon Roelofs in 1968) from the Hague and DJ Mental Theo (born Theo Nabuurs in 1965) from Den Bosch created Happy Hardcore. First commercial releases "Live at London," and issuing "Wonderful Days," That same year Charlottenburg became their first album. Old School Hardcore and On Air followed in 1996. The 10-track record Kiss Your Sweet Ears Goodbye came two years later. Charly & Theo celebrated their 25 year show at a 2 times sold out Ziggo dome in The Netherlands for 50000 fans in 2019. On the 30th of July 2022, DJ-duo Charly Lownoise and Mental Theo performed in the Ziggo Dome for the last time together.