After studies with his father and Ferdinand Böhme in his home country,[1] he became a student of Carl Reinecke at the Leipzig Conservatory, and had later studies in Berlin under Theodor Kullak, and Brussels under Louis Brassin and François-Auguste Gevaert.
[2] Clara Schumann played her last public concert in Frankfurt on 12 March 1891.
The last work she played was Brahms's Variations on a Theme by Haydn, in the piano-duet version, with Kwast as her partner.
Their daughter Mimi Kwast married his pupil, the composer Hans Pfitzner.
She was the dedicatee of Max Reger's F minor Concerto, which she premiered in 1910, and the soloist in the first Berlin performance of Busoni's Concertino, BV 292.