Of the generally named great pianists of the twentieth century, Austria's Walter Klien is one of the least known. He studied with Josef Dichler and Arturo Benedetti Michelangeli in the 1940s and was awarded two third-place prizes at the International Busoni Piano Competitions of 1951 and 1952. Nonetheless, Klien did not make his debut in the United States until 1969, concertizing most frequently in Europe. Most of Klien's recordings were made in Vienna for the American Vox label; in some cases Klien performed as part of a four-hand duet with his friend and fellow Austrian Alfred Brendel. Klien also backed up violinists Arthur Grumiaux and Wolfgang Schneiderhan in violin and piano works.
Throughout his life, Klien recorded several sets for Vox that encompass the entire known keyboard output of certain composers, including Mozart, Brahms, and Schubert. His Schubert recordings are particularly exceptional, and are widely considered on a par with or better than the series made by Alfred Brendel — lean, clean, and refined, yet expressive and deeply felt. Vox' reputation as a low-budget classical label almost assured that Klien's performances would remain undervalued during his lifetime; however, not long after Klien died, there was a sharp reversal in his critical fortunes. Although Klien's overall legacy is extraordinarily consistent and in itself rewarding, it is his Schubert cycle that represents Klien at his best.