The tenor, who is originally from Passau, took clarinet, piano and organ lessons as a child and initially studied clarinet and voice with Prof. Andreas Lebeda in Linz. He subsequently studied historical clarinet and chalumeaux as well as a master study in vocal ensemble with Anthony Rooley and Evelyn Tubb at the Schola Cantorum Basiliensis. His most influential vocal coaches were Andreas Lebeda, Clemens Morgenthaler, Kurt Widmer and Richard Levitt.

His stylistic emphasis in his repertoire are baroque oratorios and the music of the renaissance. Matthias Deger is mainly performing in Germany as a tenor soloist and ensemble singer, as composer and clarinettist in various baroque orchestras.