Brand new recordings of Brahms' Sonatas according to period performance practice. Basic features: changing of rhythm and tempo within the same movement, expressive legato, portamento and vibrato. Brahms himself played his chamber workd very freely and stated any 'sane musician' would play differently every week. Before recording, Johannes Leertwouer has made a four years research on Brahms' performing practice, conducting all symphonies and concertos.