Frederic Chopin
Chopin's mazurkas and waltzes are all in straightforward ternary or episodic form, sometimes with a coda. The mazurkas often show more folk features than many of his other works, sometimes including modal scales and harmonies and the use of drone basses. However, some also show unusual sophistication, for example Op. 63 No. 3, which includes a canon at one beat's distance, a great rarity in music. Chopin's polonaises show a marked advance on those of his Polish predecessors in the form (who included his teachers Zywny and Elsner). As with the traditional polonaise, Chopin's works are in triple time and typically display a martial rhythm in their melodies, accompaniments and cadences. Unlike most of their precursors, they also require a formidable playing technique. The 21 nocturnes are more structured, and of greater emotional depth, than those of Field (whom Chopin met in 1833). Many of the Chopin nocturnes have middle sections marked by agitated expression (and often making very difficult demands on the performer) which heightens their dramatic character. Chopin's études are largely in straightforward ternary form. He used them to teach his own technique of piano playing —for instance playing double thirds (Op. 25, No. 6), playing in octaves (Op. 25, No. 10), and playing repeated notes (Op. 10, No.  7). The preludes, many of which are very brief (some consisting of simple statements and developments of a single theme or figure), were described by Schumann as "the beginnings of studies". Inspired by J.S. Bach's The Well-Tempered Clavier, Chopin's preludes move up the circle of fifths (rather than Bach's chromatic scale sequence) to create a prelude in each major and minor tonality. The preludes were perhaps not intended to be played as a group, and may even have been used by him and later pianists as generic preludes to others of his pieces, or even to music by other composers, as Kenneth Hamilton suggests: he has noted a recording by Ferruccio Busoni of 1922, in which the Prelude Op. 28 No. 7 is followed by the Étude Op. 10 No. 5. The two mature piano sonatas (No. 2, Op. 35, written in 1839 and No. 3, Op. 58, written in 1844) are in four movements. In Op. 35, Chopin was able to combine within a formal large musical structure many elements of his virtuosic piano technique—"a kind of dialogue between the public pianism of the brilliant style and the German sonata principle". The last movement, a brief (75-bar) perpetuum mobile in which the hands play in unmodified octave unison throughout, was found shocking and unmusical by contemporaries, including Schumann. The Op. 58 sonata is closer to the German tradition, including many passages of complex counterpoint, "worthy of Brahms" according to the music historians Kornel Michałowski and Jim Samson. Chopin's harmonic innovations may have arisen partly from his keyboard improvisation technique. Temperley says that in his works "novel harmonic effects frequently result from the combination of ordinary appoggiaturas or passing notes with melodic figures of accompaniment", and cadences are delayed by the use of chords outside the home key (neapolitan sixths and diminished sevenths), or by sudden shifts to remote keys. Chord progressions sometimes anticipate the shifting tonality of later composers such as Claude Debussy, as does Chopin's use of modal harmony. Technique and performance style Extract from Chopin Nocturne Op. 62 no. 1 (1846, composer's manuscript) The same passage (1881 Schirmer edition). The examples show typical use by Chopin of trills, grace notes and detailed pedalling and tempo instructions. In 1841, Léon Escudier wrote of a recital given by Chopin that year, "One may say that Chopin is the creator of a school of piano and a school of composition. In truth, nothing equals the lightness, the sweetness with which the composer preludes on the piano; moreover nothing may be compared to his works full of originality, distinction and grace." Chopin refused to conform to a standard method of playing and believed that there was no set technique for playing well. His style was based extensively on his use of very independent finger technique. In his Projet de méthode he wrote: "Everything is a matter of knowing good fingering ... we need no less to use the rest of the hand, the wrist, the forearm and the upper arm." He further stated: "One needs only to study a certain position of the hand in relation to the keys to obtain with ease the most beautiful quality of sound, to know how to play short notes and long notes, and [to attain] unlimited dexterity." The consequences of this approach to technique in Chopin's music include the frequent use of the entire range of the keyboard, passages in double octaves and other chord groupings, swiftly repeated notes, the use of grace notes, and the use of contrasting rhythms (four against three, for example) between the han