She studied at the Stern Conservatory with Hermann Weißenborn and Gerty König and made her debut as Kate Pinkerton in Madama Butterfly at the Deutsche Oper Berlin in 1962.

She went on to sing various roles there over nine seasons, including the parts of Donna Anna (Don Giovanni) and the Queen of the Night (The Magic Flute), as well as Liù in Puccini's Turandot.

She was one of the original performers of Hans Werner Henze's oratorio Das Floß der Medusa which she created on disc because the intended premiere in Hamburg was cancelled after a classical music riot.

Opera News has said in a review of a series of recordings made in the 1980s that Moser could sing with a "finely controlled" legato.

She gave several concerts in Germany with Ivan Törzs at the piano (Dresden, Semperoper 1997, Stadttheater Gießen (1999) with programs ranging from Johann Adolph Hasse to Clara Schumann and Richard Strauss.