Krenn received his first musical training as a member of the boys' choir Wiener Sängerknaben.
[1] Krenn made his operatic debut in The Fairy Queen at the Berlin Deutsche Oper.
Krenn performed in Salzburg in Beethoven’s Missa Solemnis, conducted by Herbert von Karajan.
[1] The Musical Times said of him in 1971, "Werner Krenn's voice is sweet and true and earnest".
[3] He has performed with the Scottish Opera and the BBC International Concert at the Royal Festival Hall.