Webern and the Austrian composer Alban Berg were Schoenberg’s most important disciples. Webern’s early works, such as the Passacaglia (1908) for orchestra, are richly scored, heavily chromatic works in the postromantic style. His music during the period between his Six Pieces (1910) for orchestra and the Five Canons (1924) for soprano and two clarinets was marked by sparse textures, small instrumental ensembles, and highly compact musical construction. With his 1924 work Drei geistliche Volkslieder (Three Spiritual Folksongs) he adopted Schoenberg’s newly formulated twelve-tone system. His subsequent works remain notable for their extreme condensation, brevity, great clarity and delicacy, and fragmentary melodic units. Webern extended the twelve-tone concept of serialization of pitch to serialization of rhythms, dynamics, and tone colors.