large measure intended, for improvisational enhancement, not only of the treble parts but also, almost by definition, of the bass, which was figured to suggest no more than a minimal chordal outline." Improvised accompaniment over a figured bass was a common practice during the Baroque era, and to some extent the following periods. Improvisation remains a feature of organ playing in some church services and are regularly also performed at concerts. Dieterich Buxtehude and Johann Sebastian Bach were regarded in the Baroque period as highly skilled organ improvisers. During the 20th century, some musicians known as great improvisers such as Marcel Dupré, Pierre Cochereau and Pierre Pincemaille continued this form of music, in the tradition of the French organ school. Maurice Duruflé, a great improviser himself, transcribed improvisations by Louis Vierne and Charles Tournemire. Olivier Latry later wrote his improvisations as a compositions, for example Salve Regina. Classical period Keyboard improvisation Classical music departs from baroque style in that sometimes several voices may move together as chords involving both hands, to form brief phrases without any passing tones. Though such motifs were used sparingly by Mozart, they were taken up much more liberally by Beethoven and Schubert. Such chords also appeared to some extent in baroque keyboard music, such as the 3rd movement theme in Bach's Italian Concerto. But at that time such a chord often appeared only in one clef at a time, (or one hand on the keyboard) and did not form the independent phrases found more in later music. Adorno mentions this movement of the Italian Concerto as a more flexible, improvisatory form, in comparison to Mozart, suggesting the gradual diminishment of improvisation well before its decline became obvious. The introductory gesture of tonic, subdominant, dominant, tonic, however, much like its baroque form, continues to appear at the beginning of high-classical and romantic piano pieces (and much other music) as in Haydn's Piano Sonata Hob. XVI/52 and Beethoven's Sonata No. 24, Op. 78. Beethoven and Mozart cultivated mood markings such as con amore, appassionato, cantabile, and expressivo. In fact, it is perhaps because improvisation is spontaneous that it is akin to the communication of love. Mozart and Beethoven Beethoven and Mozart left excellent examples of what their improvisations were like, in the sets of variations and the sonatas which they published, and in their written out cadenzas (which illustrate what their improvisations would have sounded like). As