Mattias holds a Graduate Diploma in Voice from the Queensland Conservatorium Griffith University and an Honours Degree in music from Elder Conservatorium Adelaide.  He has performed as soloist and chorus member with Opera Queensland, State Opera of South Australia, Opera Australia, West London Opera, Guildford Opera, Underground Opera and with the touring companies Co-Opera and Oz Opera.

Operatic roles include Aeneas/The Sailor (Dido and Aeneas), Rinuccio (Gianni Schicchi), Le Mari (Les Mamelles de Tirésias), Beppe (I Pagliacci), Don Jose/Remendado (Carmen), Camille (The Merry Widow), Cassio (Otello) and Chuck/Doctor in the Australian premiere of The Perfect American. 

Mattias has also performed Tom/The Son in Ross Edwards' Christina's World, which was broadcast on ABC Classic FM.  Mattias has appeared as tenor soloist in performances of Mendelssohn’s Elijah and Lobgesang, Mozart’s Coronation Mass, Berlioz’ The Childhood of Christ, Britten’s Saint Nicolas, Handel’s Israel in Egypt and Messiah (Queensland Orchestra and Dubrovnik Symphony Orchestra) and Rossini's Petite Messe Solenelle in St John's Smith Square, London.