Historical Documents on Keyboard Improvisation

During the 18th and 19th centuries, the technological improvements of the industrial revolution introduced cast iron as a crucial ingredient in the manufacturing of the pianoforte instrument. As a result, the sound of the pianoforte was able to compete with that of an orchestra, and public concerts and recitals involving pianists became increasingly common. During this time, treatises dedicated entirely to keyboard improvisation were written by Andre Gretry (1741–1813), Carl Czerny (1791–1857), and Frederic Kalkbrenner (1785–1849). Furthermore, C. P. E. Bach (1714–1788), Daneil Turk (1750–1813), Johann Hummel (1778–1837), and Ignaz Moscholes (1794–1870) wrote about keyboard performance, including discussions on improvisation. All of these authors provide rich information and contexts for piano performance practices through the 18th and 19th centuries.

C. P. E. Bach was a remarkable composer, keyboardist, teacher, and writer. In his treatise, Essays on the True Art of Playing Keyboard Instruments, completed in 1762, chapter seven is devoted to improvisation. Daneil Turk’s School of Clavier Playing was published in 1789. As a respected organist and music theorist, Turk focused on improvisation and performance. André Gretry was a famous French composer and music theorist, who wrote fifty operas. Published in 1802, his treatise Simple Method to Learn to Prelude in Time with All Harmonic Resources teaches music theory, such as the fundamental bass system, in the practice of keyboard improvisation. Johann Hummel was a teacher of Czerny and was a great keyboard improviser. His concerts often featured improvisation (Fantasia) at the end as a conclusion of the program. Published in 1827, his Instructions for Playing the Pianoforte documents his own pathway of acquiring improvisation skills. Carl Czerny, a student of Beethoven and a teacher of Liszt, wrote extensively on the art of improvisation. His opus 200, A Systematic Introduction to Improvisation on the Pianoforte, was published in 1829. This treatise provides a systematic approach to the structure of improvisation and its relation to written composition. In 1839, Czerny published another treatise, Complete Theoretical and Practical PianoForte School, opus 500, in which he discusses fantasia and preluding. Ignaz Moscheles was a famous piano virtuoso and composer, who had close interactions with Liszt. He wrote his treatise Method of Methods of Piano in 1840 in which he discusses coherence of improvisation in relation to composition. Frederick Kalkbrenner was also a famous pianist, who was once Chopin’s teacher. Written in 1849, his opus 185, Treatise on Harmony for the Pianist, Rational Principles of Modulation to Learn to Prelude and Improvise teaches music theory and its application to piano improvisation.

This essay attempts to summarize these eight treatises, focusing on keyboard improvisation and following their common threads, including discussions on spontaneity and structure, chromaticism and tonal stability, improvisation and composition, and the aesthetic framework that had evolved during the 18th and 19th centuries.

In his treatise, C. P. E. Bach articulates some germinal ideas which later authors commented and elaborated on. His writing on improvisation is nuanced and organized. According to C. P. E. Bach, the essence of a fantasy, which was the most important and substantial genre of keyboard improvisation, is its freedom in meter and modulation: “A fantasia is said to be free when it is unmeasured and moves through more keys than is customary in other pieces, which are composed or improvised in meter.” This statement establishes two of the main characteristics of improvisation: exploration of musical time and harmonic space. Although the performers have control over musical time and harmonic space in a fantasy, their freedom is subject to constraints. For example, when advocating structural rules, C. P. E. Bach writes that “a key in which to begin and end must be established. Although no bar lines are employed, the ear demands a definite relationship in the succession and duration of the chords themselves…a relationship in the lengths of notes so that the piece may be notated.” He confirms the established perception of a composed piece as written out improvisation. Evaluating improvisation according to its structure and resemblance to an actual composition became more emphasized and crucial in the 19th century treatises.

C. P. E. Bach believes that chromaticism is a principal feature of a fantasy: “Strange and profuse modulations are not recommended in pieces performed in strict measures, but a fantasia with excursions to only the next related keys would sound too plain.” According to C. P. E. Bach, the most convenient chord for chromatic modulation is the diminished seventh chord, as “by inverting it and changing it enharmonically, a great many chordal transformations can be attained.” Although chromaticism is one of the key features of a fantasy, C. P. E. Bach also points out that tonality has to be substantially established, and the recapitulation of the initial musical material in the principal key needs to create an impression to the listener. He notes that “the principal key must not be left too quickly at the beginning nor regained too late at the end. At the start the principal key must prevail for some time so that the listener will be unmistakably oriented. And again before the close it must be well prolonged as a means of preparing the listener for the end of the fantasia and impressing the tonality upon his memory.” Tonal stability therefore becomes an important factor in the musical form of improvisation.

C. P. E. Bach believes that fluency in music theory is the foundation of improvisation: “A thorough understanding of harmony and acquaintance with a few rules of construction.” He employs the fundamental bass system in teaching and practicing improvisation, noting that “a keyboardist, particularly one of limited ability, may avail himself in extemporizing: with due caution he fashions his bass out of the ascending and descending scale of the prescribed key, with a variety of figured bass signature.” To view improvisation as music theory in practice was later focused on and developed in 19th century treatises as well.

Turk’s writing on improvisation is limited, appearing at the “supplement” section of his Klavierschule. Turk does not discuss improvisation itself. Instead, he discribes three types of improvisation in a dictionary manner: fantasie, capriccio, and praeludium. On fantasie, Turk agrees with C. P. E. Bach on the spontaneity and freedom that a performer possesses that “a fantasie is called free when its creator neither holds to a certain main subject (theme) nor to meter or rhythm, when he roams around in his modulations, when he expresses various and often contrasting characters, in short, when he follows his whims completely without attempting to work out a specific plan.” He also documents a type of strict fantasy, “in which a meter is fundamental, in which there is a greater adherence to the laws of modulation, and in which a greater unity is observed, etc.” Turk’s writing provides evidence that it was common for musicians to perform written out fantasies, instead of improvising them on the spot. Turk writes that “The fantasie, for the most part, is first contrived during the performance, but there are also fantasies which, like other compositions, have already been composed and notated.” Turk implies that performers occasionally performed notated fantasies that appeared to be improvisatory. This aesthetic view on the relationship between improvisation and composition was developed later in the 19th century, when writers valued improvisation that resembled a well-structured composition.

At the turn of the 19th century, Gretry wrote a practical and pedagogical treatise on harmony and keyboard improvisation. Its content was designed for beginners of keyboard improvisation. Gretry wrote that his fifteen-year-old niece was able to follow the treatise and “after doing this harmonic course, one can no longer ignore the fundamental bass system.” Similar to C. P. E. Bach, Grétry’s treatise utilizes harmonic theory to exemplify the practice of piano performance, claiming that “the fundamental bass is the unequivocal proof of the validity of the chords.” A focus of Gretry’s treatise is modulation using sequences. For example, while discussing descending thirds, he writes that “it is necessary to go through all twenty-four modulations of the two major and minor scales, by chaining them together with the relative keys.” And in discussing descending fifths, he notes that “when descending from a fifth and ascending by a fourth, or ascending by fourths and descending by fifths, it is a necessary move that almost all bass can come out of it.” These are the ways of achieving the chromatic effect that C. P. E. Bach and Turk documented in their writings. Gretry also calls the diminished seventh chord “the sensitive seventh in the minor mode,” which he recommends for modulations.

In his treatise, Gretry articulates an idea that is not presented by C. P. E. Bach and Turk, that a keyboardist should study compositions in genres in which one hopes to improvise. He writes that “if our student wants to succeed in making fugues more rigorous than those which I call improvised fugues, he should study the fugues of Handel, of Scarlatti. . . let him analyze them, learn them by heart.” He then wrote: “I gave an almost similar advice to young composers, men or women, who could not manage to compose a sonata: take, I told them, a sonata from a good master; with melodious or harmonious ideas which are yours, follow it almost in all its modulations or transitions of tones; your sonata will be good; it will, at most, have a familiar resemblance to its model.” It is almost as if Gretry does not distinguish the creative processes between composing and improvising when he offers his advice, at least from the perspective of training. It is important to utilize memorization of the existing compositions and treat them as existing models. This was elaborated by later authors, such as Kalkbrenner and Hummel. This is different from the memory of the tonal coherence which C. P. E. Bach stressed.

Kalkrenner’s treatise was published as his opus 185 and is the most practical among cited treatises. His text contains mostly descriptions of the chords and chordal progressions he exemplifies. There is no discussion until the very end, where he provides some comments without much elaboration. Similar to Gretry, Kalkbrenner focuses on sequences and modulations in his treatise. He writes that the purpose of his treatise is to “apply harmonies to the progressions or chord sequences, in order to learn to prelude and to improvise.” He encourages young pianists to utilize memory and to know the harmonic patterns “by heart.” He also emphasizes that imitation requires practicing constantly, implying that improvising a canon, for example, is a difficult skill. Lastly, he recommends the same as previous authors regarding the utility of diminished seventh chords in modulations. Essentially, Gretry and Kalkbrenner wrote music theory books, except the theory is manifested through performance on the pianoforte. Their writing could serve as stepping stones for studying Czerny.

Czerny’s treatises on improvisation are for already skilled pianists. They are not practical, but are extremely valuable for theorists and musicologists. For Czerny, improvisation is a product of excellent musicianship. Being a good improviser requires keyboard training from an early age, a wide knowledge in theory of harmony, and finally, “a completely perfected technique of playing (virtuosity).” Czerny’s standard for virtuosity is the ability to perform everything that is wished, which includes in all difficulties and in all keys, “as well as in everything that pertains to beautiful, pleasing and graceful performance.” His writing explains what is possible in an improvisation, but it does not help one to get started. For example, when Czerny discusses the choice of thematic material in Fantasia: “every theme, without exception, and even if it were to last for only two arbitrary tones, can serve by means of several modifications in meter and rhythm as the opening of all species of compositions that exist in the realm of music.” Later when explaining how to further improve one’s craft, he wrote: “it facilitates the task to start by selecting suitable models for this purpose. Thus for the first type (Allegro), the first movement of a good sonata (by Clementi, Beethoven, Hummel, etc.) can serve as a model.” These suggestions are not necessarily just for improvisation. They apply to composers as well. What Czerny documented was a method of studying Western music.

On improvisation, Czerny wrote in his opus 200 that “when the practicing musician possesses the capability not only of executing at his instrument the ideas that his inventive power, inspiration, or mood have evoked in him at the instant of their conception but of so combining them that the coherence can have the effect on the listener of an actual composition — this is what is called: Improvising or Extemporizing.” Ten years later, in his opus 500, he wrote that “By “extemporizing” we are to understand, that the Performer, on the impulse of the moment, without preparation, and often too without reflection, plays something, which if we may say so, comes spontaneously under his fingers, and which nevertheless possesses to a certain degree, all the properties of a written Composition, and in which, consequently, Melodies and brilliant passages alternate in a tasteful or elaborate manner.” These two quotes of Czerny contain similar structure. Initially, he re-states the importance of spontaneity, already documented by C. P. E. Bach and Turk, but in the second half, he incorporates the Beethovenian obsession about form and structure into the aesthetics of keyboard improvising. It is justifiable to view Czerny’s treatises as an investigation into the possibilities of musical forms for improvised keyboard music.

Czerny’s aesthetics on improvisation focuses on form and structure. He documents nine musical forms one may choose as frameworks to improvise a fantasy:

“a.Allegro (probably as the first movement of a sonata)

b.Adagio (in the serious style)

c.Allegretto grazioso (unadorned or with embellishments in the gallant style)

d.Scherzo presto (a capriccio)

e.Rondo vivace

f.Polacca

g.Theme for variations

h.Fugue (also Canon frequently)

i.Waltz, Ecossaise, March, and the like”

After discussing each form, Czerny concludes that the most difficult of all Fantasies is the kind which combines “several styles into one and the same fantasy. One might begin with Allegro, for example, develop it for some length of time, then proceed into an Adagio or Andantino, interweave it with a fugal section and with the kind of modulatory section discussed in the first chapter, and conclude with a lively rondo. With this procedure, there already exists a complete fantasy on a single theme constituting an orderly totality, one in which unity and a distinct character can prevail.” It has already been articulated in recent scholarship on keyboard improvisation by Katrin Eggers and Micharl Lehner that Czerny’s opus 200 is the source of Schubert’s Fantasy in C major as well as the double-function form which Liszt’s Sonata in B minor employs.

Hummel’s writing on improvisation is a good pair with Czerny’s opus 200. They were written around the same time and there is a lot of synergy in their writings. To play a fantasy is when an artist “wants to devote himself to his thoughts and feelings in his art without any particular intention.” Hummel warns that a player should not play “too long in the same form and mood.” Hummel then describes a musical experience that is very similar to Czerny’s description of a full-fledged Fantasy, in which several distinct movements are combined: “after the fantasist has played, for example, for a while in a serious - be it in celebratory or fiery mood or movement, and also in a continuous manner of execution - he now slips unnoticed into a gentle, friendly melody and treats it quite simply for a while; or, conversely, that once he has finally performed such a melody, he continues it a little more animatedly, but now he takes it to a completely different side, be it as a powerful theme, counterpoint elaboration, or as a guide and, as it were, as a constantly recurring refrain for free, happy, humorous play, and so on.” Similar to Czerny, Hummel’s statement suggests that a remarkable fantasy consists of a theme and its developments in different yet continuous styles or forms, which include contrasting moods and textures.

As a great improviser, Hummel’s thoughts on improvisation are nuanced. Similar to Czerny, he believes that a thorough education in harmonic theory and virtuosic keyboard skills are the foundation of keyboard improvisation of fantasies. He wrote that “no matter what key the player is in, do what the mind thinks, and do it without the need for a clear consciousness of these mechanical accomplishments.” This portrays not only a spontaneous and dream-like playing, but also a very high level of keyboard skill as a pianist could achieve virtuosity without being aware of such accomplishment. He then wrote, according to his own experience, that “after I had mastered playing the piano, harmony with all its twists and turns, the way of modulating correctly and well, enharmonic confusion of tones, counterpoint, etc., to such an extent that I was able to practice them practically, and my talent for my own invention (my ability to create musical ideas out of myself), as the first requirement to be presupposed in all fairly significant free fantasizing. Through the diligent playing of the most excellent old and newer compositions, I had expanded, nourished, enriched my taste, cleaned, elevated and strengthened it. My way of arranging and connecting musical ideas, developing and executing them, had become clearer and more fluent.” Similar to Gretry and Czerny, Hummel also stresses the importance of studying old and contemporary compositions for improving one’s musicianship and “taste.”

Similar to the nature of Gretry and Kalkbrenner treatises, Hummel believes that keyboard improvisation is a skill that can be acquired through training. When discussing how he himself learnt to improvise, he writes that “I directed my attention primarily to a good connection and continuation of the ideas, to a strict rhythm with all the diversity of expression and character, to alternating coloring through the diversity of the types of presentation, richer or more economical figuration, modulation, decoration and the like.” According to Hummel, this is not an ideal improvisation, but a process that one needs to go through in order to improve. Once improvement is achieved through years of training, Hummel writes that “I tried to fantasize, but for a long time only in front of a few people, some experts, some non-experts, and at the same time quietly observe what effect what was presented had on both parts of my small, mixed audience, trusting far less in their words upon completion than in their expressions and other movements as my playing progressed.” This step involves the interaction between performer and the audience. Hummel articulates that improvising for a small circle is very different from improvising in front of the public. It is a challenge for any improviser to produce music that would satisfy both experts and amateurs. It is worth noting that Hummel was the only writer that extensively emphasized the differences between audiences in small circles and the public sphere.

Moscheles defines improvisation as “to compose without erasing.” Similar to C. P. E. Bach and Czerny, the need for a plan and structure is therefore crucial. The return or recapitulation of the main idea is necessary to create the effect of a meditated composition. He considers the musical product of improvisation as of lower value than a well-thought composition. No matter how skilled an improviser is, there will always be “some disorder, some repetitions in the premature fruit of his thought, and sometimes his sleepy imagination will let him wander in vagueness.” His criticism of improvisers is similar to what Hummel describes as a delay of musical thoughts. Moscheles recommends virtuosity and audacious risk-taking during improvisation to balance its inadequacy compared with compositions. Similar to C. P. E. Bach, Gretry, Kalkbrenner, and Hummel, Moscheles also believes that to improvise is a skill that requires experience and training.

In conclusion, during the 18th and 19th centuries, keyboard improvisation was a crucial aspect of pianoforte performance. The aesthetics of this activity evolved together with corresponding methodology and music theory. Although tonal structure and formal unity are defining elements of improvisation, for C. P. E. Bach and Turk, the more important aspects of improvisation are spontaneous execution and chromatic harmonic space. Gretry and Kalkbrenner’s treatises focus and demonstrate the importance of studying music theory and their applications in the practice of improvisation. The fundamental bass system and harmonic sequences are crucial tools for a performer to achieve fluent and meaningful construction of an improvisation. Czerny, on the other hand, contributes the most towards our knowledge on thematic development and formal structures of improvisation. Along with Hummel, their descriptions of the grandest form of fantasy contain clear similarities to the so-called double-function sonata form. Gretry, Czerny, Hummel, and Moscheles’ treatises emphasize the importance of studying composition to improve one’s musicianship and improvisation. They articulate the 19th century standard of improvisation to be akin to performance of a written composition.

Bibliography

Bach, Carl P. E. Essays on the True Art of Playing Keyboard Instruments. Translated by William Mitchell. New York: Norton, 1949.

Czerny, Carl. A Systematic Introduction to Improvisation on the Pianoforte: Opus 200. Translated by Alice L. Mitchell. New York: Longman Inc., 1983.

Czerny, Carl. Complete Theoretical and Practical Pianoforte School. Opus 500. Translated by James A. Hamilton. London: R. Cocks & Co., 1839.

Eggers, Katrin, and Michael Lehner. “Freedom and Form in Piano Improvisation in the Early 19th Century.” In The Routledge Handbook of Philosophy and Improvisation in Arts, edited by Alessandro Bertinetto and Marcelo Ruta, 343-354. London: Taylor & Francis Limited, 2021.

Gretry, Andre-Ernest-Modeste. Méthode Simple Pour Apprendre À Préluder En Peu Temps Avec Toutes Les Ressources De L’harmonie. Paris: Imprimerie de la République, 1802.

Hummel, Johann N. Anweisung zum Piano-Forte-Spiel. Vienna: Tobias Haslinger, 1827.

Kalkbrenner, Frederic. Traité d'Harmonie Du Pianiste, Principes Rationnels De La Modulation Pour Apprendre À Préluder Et À Improviser, Opus 185. Amsterdam: Heuwekemeyer, 1970.

Kroll, Mark. Johann Nepomuk Hummel: A Musician’s Life and World. Lanham, Maryland: The Scarecrow Press, 2007.

Moscheles, Ignaz. Methode Des Methodes De Piano. Paris: Maurice Schlesinger, 1840.

Turk, Daneil G. School of Clavier Playing. Translated by Raymond H. Haggh. Lincoln: University of Nebraska Press, 1982.