- The second part of TrioVanBeethoven's complete series of piano trios starts out with the Trio in B flat, op. 97 ('Archduke'), one of Beethoven's most popular and extensive trios. - Although only published in 1824, Beethoven's 'Cockatoo Variations', op. 121a, based on a popular song from the musical comedy Die Schwestern von Prag by composer Wenzel M�ller, must have begun around the beginning of the 19th c., thus providing for both early and late stylistic features. - The Allegretto for the Piano Trio in E flat, Hess 48 (1784) on the other hand, constitutes a truly early work by Beethoven.