A primary goal in the teaching of piano in the applied studio environment is enabling students to interact with their own performances throughout the learning process. Not only is feedback from the applied teacher important, but the feedback that students can generate for themselves based upon recorded performance can also be extremely valuable. Technological tools are now available which easily allow students to hear as well as "see" their performances, thus providing a platform upon which both student and teacher can engage in discussion regarding the many aspects of piano performance.
    The Yamaha Disklavier is an instrument that combines a Yamaha acoustic piano with optical sensors. These sensors allow for a very high level of accuracy in playback through the onboard computer controls of the instrument. MIDI connections also allow for recording and/or playback through an external sequencer program. The Disklavier records the speed of each hammer which is engaged as well as the movements of the pedal. Playback is an exact replication of notes, rhythm, dynamics, articulation and pedaling.
    The computer program, Cakewalk Professional Version 5.0, is a well-known MIDI sequencing program. When used in a setup with the Disklavier, the recorded performance can be accessed at any specific point and replayed as many times as needed, thus economizing the time used in searching for specific measures in the musical performance for playback. The metronome feature allows the tempo to be modulated easily to other levels. Performance data can be routed to other devices such as an external tone generator in order to change the orchestration of the performance from piano to another instrumentation such as strings.
    The Disklavier, alone as well as interfaced with Cakewalk, has been used in several ways in my studio teaching in recent months. This setup has provided a very helpful tool in allowing students to experience their performances in different ways, often resulting in new musical insights. The following scenarios serve to illustrate various applications of this technology for use in the applied piano studio.

Performance Accuracy
    Fundamental for the piano student is the need to perform passages correctly with regard to notes, rhythm and pedaling. The Disklavier is well suited to enable students to play and record a passage in order to observe the accuracy of these aspects. This can be illustrated with the Piece Solfeggietto, Wq. 117/2, by C. P. E. Bach (see Figure 1). An inherent rhythmic challenge of this piece for some students is the production of evenly controlled sixteenth notes at a rapid tempo (e.g. Prestissimo, q.n. = 132). The tempo controller of the Disklavier provides a means of decreasing the tempo prior to playback in order to facilitate listening for temporal evenness in playing the rapid sixteenth note passages.

Figure 1. Solfeggietto, Wq. 117/2, measures 1-4, by C. P. E. Bach.

Rhythmic Drill
    Another problem for pianists is the playing of difficult cross-rhythms between the two hands. Two related yet different tasks are necessary in order for the student to achieve musical results. First, the student must hear the two rhythms in relation to each other. Secondly, the physical coordination of playing each hand independently must be achieved. A passage from Villa-Lobo's Alegria na horta, Op. 97 (see Figure 2) illustrates this technical challenge. In order to drill this, the student could record the left-hand part (a series of eighth notes) and during playback, drill the right-hand part against the recorded part. The drill would commence with a slow tempo and, after sufficient repetitions, gradually increase until a performance tempo is achieved. The recording and playback features of the Disklavier allow both parts to be recorded separately. During playback either part may be muted which allows the student to drill each part separately while hearing both parts. The tempo controller allows changes of tempo which can accommodate the technical skill acquisition.

Figure 2: "Alegria na horta" from Suite floral, Op. 97, measures 25-29, by Hector Villa-Lobos.

The Melodic Line and Articulation
    Shaping the melodic line and choosing an articulation pattern in performance of fugal subjects, such as those found in the Well-Tempered Clavier of J. S. Bach, can provide a challenge to students. Again, a high degree of listening is necessary. The student must hear the relative intensity of each note of the subject in order to shape the line. Similarly, the exact duration of each note in the metrical context will provide a definition of the articulation of the fugal subject. The subject of Bach' s well known Fugue in C Minor, WTC I (shown in Figure 3), provides an interesting example in terms of its possibilities regarding both its melodic shape and articulation

Figure 3: Fugal subject from Fugue in C Minor, WTC 1, by J. S. Bach.

    Interfacing the Yamaha Disklavier with Cakewalk allows students to visually and aurally observe what they are doing with regard to melodic line and articulation. Recording the fugue subject with Cakewalk allows the student to observe the relative intensity of each note on a continuum of 0 to 127 (a measure of keystroke velocity). The numbers associated with each note provide a detailed description of the dynamic structure of the recorded performance. Through Cakewalk the tempo can be modulated in order to listen to the example at a reduced speed, thus allowing a more careful aural analysis. In the Event List window, Cakewalk also provides a graphic presentation of the intensity of each note. (See the middle column under "values" in Figure 4.)

Figure 4: Cakewalk's Event List Window.

    The articulation pattern of the performance of the fugal subject can be studied by accessing the Piano Roll view of Cakewalk as shown in Figure 5. Here the student can visually see the duration of each note. Overlapping or connected notes indicate legato while disconnected notes show a degree of staccato. The amount of "space" between successive notes visually illustrates the degree of staccato performed. The Disklavier also provides a visual representation of articulation as the student observes the depression and release of keys during playback.

Figure 5. Cakewalk's Piano Roll View.

Voicing
    In many piano pieces, the musical content is multilayered. In such contexts there exists the challenge for students to appropriate tonal balance among these layers. Sometimes it is difficult for the student to hear a certain melodic line, particularly in thickly textured passages. Recording the passage and then playing the melodic line with a contrasting, sustaining timbre (such as strings) along with the playback can help students to hear those layers in musical context. A sustaining timbre can also help the student focus on longer notes which may be difficult to hear considering the rapid decay characteristic of the piano tone. in measures 14-22 of Chopin's Nocturne, Op. 72, No. 1 (see Figure 6), there are at least three layers of musical material which the student must hear: the melody, the counter-melody, and the left-hand accompaniment. By first recording the complete passage using Cakewalk, the passage can be played back. Additionally, however, the Disklavier may be connected (via MIDI out) to a General MIDI tone module (such as the Yamaha Disk Orchestra Unit DOU-10). Under the Function/Edit controls, the Disklavier's MIDI Out options can be set to choose any General MIDI instrument. In this case, Program #41 (Violin) has been chosen. The Transposition setting is set to -24 in order to allow the student to play two octaves higher than the notated pitches and yet hear the pitches as notated. This is done in order that the keys will not interfere with the keys being depressed during playback of the original passage. Now during playback, the student may play the melody or counter-melody as a violin part in order to highlight it within the entire musical texture. This may aid the student in listening to distinct parts of the musical whole.

Figure 6: Nocturne, Op. 72, No. 1, measures 14-22, by Chopin

Orchestration
    Another interesting use of the Disklavier connected to a tone module is illustrated by experimenting with the sound "ideal" of Mozart sonatas and other early Classical works (see Figure 7). Since so much of the performance practice regarding keyboard articulation grew out of violin bowing, "re-creating" the classical sound ideal by applying a string orchestration to a keyboard work can be a valuable musical experience. By connecting the Disklavier (via N41DI Out) to the tone module and selecting a string sound, the student may experiment with the sound ideal and practice various forms of articulation. Using the muffler pedal will reduce the volume of the piano timbre as the Disklavier is being played.

Figure 7: Sonata in F Major, first movement, measures 1-12, K. 332, by Mozart

Conclusion
    There are many positive aspects of using the Disklavier with the Cakewalk program and with a tone module during piano lessons. Students often remark about how "obvious" certain aspects of their performance become once encountered from both an aural and a visual point of view. Students can literally "see" an articulation, for example, by viewing the keys depressed and released during playback of a performance or by observing the Piano Roll view of Cakewalk. Pedaling can be analyzed by viewing exactly how it was used in recording as the pedal moves during playback. The recording and metronome capabilities of the Disklavier and Cakewalk enable students to isolate more easily the various components of complex performance skills, both for diagnostic purposes and for rehearsal of those specific skills. Finally, students can learn to listen more carefully as the technology allows them to focus their attention on particular aspects of performance.