Friedberg studied piano with James Kwast and with Clara Schumann at the Hoch Conservatory, Frankfurt.

His pupils include Gertrude Lightstone Mittelmann, William Browning,[1] Malcolm Frager, Edith Weiss-Mann, Bruce Hungerford, Reginald Bedford, Nina Simone, William Masselos, Frances Ziffer, and Elly Ney.

[2] In 1893 he had given an all-Brahms recital in the presence of the composer, who highly admired his playing and who later coached him in private on the performance of the majority of his piano works.

As a chamber musician he replaced Artur Schnabel in the Schnabel-Flesch-Becker Trio in 1920 and played in that ensemble until 1932.

Friedberg gave many recitals with Fritz Kreisler throughout America and in 1937 formed his own trio with Daniel Karpilowsky and Felix Salmond.