The son of the organ composer Josef Förster, he studied at the Prague Conservatory and was organist at several Prague churches and music critic of Národní Listy. From 1893 to 1903 he lived at Hamburg, Ger., where he became a friend of Gustav Mahler (Mahler, Gustav) and taught at the conservatory. He was music critic of Die Zeit (Zeit, Die) in Vienna (1903–18) and from 1919 professor (later director) at the Prague Conservatory.

Förster's works were mainly for chorus and solo voice, often based on religious texts. He also wrote five symphonies and several operas, notably Nepřomoženi (1918; The Invincibles), Srdce (1923; The Heart), and Bloud (1936; The Simpleton). Though Förster's Romantic and religious outlook suggests Mahler, his simpler, lyrical works, notably the song cycle Liebe, show his allegiance to the heritage of Dvořák and Smetana.