Task: Text Categorization
Input (English): The slow movement of this composer's cello concerto features a duet between the soloist and the principal cellist of the orchestra. One of his solo piano works originally contained an extra five Variations which were restored by Brahms, and that work is based on a theme by Baron von Fricken. Much of this composer's music criticism is structured as a conversation between a character representing his passionate side and one representing his dreamy side. This composer, who created (*) Florestan and Eusebius, also wrote the Symphonic Etudes as well as another piano collection with movements called "The Rocking Horse Knight" and "Traumerei." For 10 points, name this German composer of Carnaval and Kinderszenen, many of whose works were premiered by his wife Clara.
Output (English): Fine Arts