Watch Sadisflix. Academician and piano expert David Dubal narrates this absorbing documentary chronicling the instrument's history and featuring some of the 20th century's finest pianists via archival film clips. Among the keyboard virtuosos are Vladimir Horowitz, Claudio Arrau, Van Cliburn and Glenn Gould. Extras include Arrau's 1983 performance of Ludwig van Beethoven's Piano Concerto no. 4, accompanied by the Philadelphia Orchestra under maestro Riccardo Muti.