text: Felix Mendelssohn sightread a part for a piece of this type for its 1842 premiere, and suggested the addition of a second trio for its third movement Scherzo.
full_question: Felix Mendelssohn sightread a part for a piece of this type for its 1842 premiere, and suggested the addition of a second trio for its third movement Scherzo. Another piece of this type begins with an F minor theme played in unison, and was originally conceived as a string quintet, then a sonata for two pianos, by its composer Johannes Brahms. Robert Schumann's E Flat Major piece of this type established it as a standard chamber music genre, but an earlier piece of this type contains a theme and variations on the lieder "Die Forelle." That piece of this type is nicknamed "Trout." For 10 points, name this genre of music written for a string quartet plus piano.
first_sentence: Felix Mendelssohn sightread a part for a piece of this type for its 1842 premiere, and suggested the addition of a second trio for its third movement Scherzo.