He made his debut as a singer playing Sporting Life in Porgy and Bess at the Stora Theatre in Gothenburg.

His roles there included the title part in Fra Diavolo, Paris in La belle Hélène and Danilo in The Merry Widow, through 1955.

[2] Grundén played Danilo in many opera houses in Germany, including Hamburg, Munich and the Deutsche Oper am Rhein.

In Sweden he sang the role in a production at the Malmö City Theatre under the direction of Ingmar Bergman in 1954.

[2] For the gramophone, Grundén recorded the role of Danilo for Decca in the first stereophonic recording of The Merry Widow, produced in 1958 by John Culshaw, with Hilde Gueden, Waldemar Kmentt and Emmy Loose and the Vienna Philharmonic Orchestra conducted by Robert Stolz.