Mattias Olsson (born 9 January 1975) started his career as a classical percussionist playing in orchestras and big bands on Ekerö outside of . As a sideline to recording and producing bands Mattias Olsson writes articles (music related) for several Swedish Magazines.
He was born in Hong Kong to Swedish parents. In 1981 he moved to Stockholm. Starting as a drummer at eight years old he started off playing in big bands, pop and classical ensembles.
When he was 17 he joined progressive rock band Änglagård. Änglagård consisted of musicians from Ekerö as well as Waxholm. The band was heavily influenced by bands such as King Crimson, Yes and Genesis but also listened to less famous bands such as Shylock, Cathedral and Yezda Urfa. Änglagård quickly became known for their instrumentation skills and their dynamic range often reminiscent of classical music. When the band started the current trend in progressive rock was to use the newest digital equipment. Änglagård decided instead to use old classic prog equipment like the Rickenbacker bass, Minimoog and the Mellotron. Änglagård recorded two studio albums in the 1990s, Hybris (1992) and Epilog (1994). They also recorded a live album called Buried Alive (1996). The title was a joke from Mattias, the worst title for a live album must be ...Buried Alive. After a long hiatus the band released their third album Viljans Öga in 2012.
He also did some sessions with White Willow and Pär Lindh.