Understanding Piano Playing through MIDI: Students' Perspectives on Performance Analysis and Learning

Article excerpt

In language, if inflection and nuance enhance the effect of the spoken word--in music they create the meaning of notes. (1) The notated score cannot conceivably provide all the indications that must be observed for the performance of a piano piece to be musically satisfactory. These elements can be best understood through the detailed study of the performance itself.

Much of the research on expressive performance has been concerned with the analysis of skilled performances. Several researchers have demonstrated that music performances are characterized by somewhat systematic variations in timing and intensity from the strict mechanical regularity of the musical scores that are related to music structure. (2, 3, 4, 5, 6)

Comparative performance analysis can aid students in their perception and understanding of the many simultaneous dimensions of musical experience one must attend to in performance. One of the biggest stumbling blocks for students is to successfully attend to all the subtleties of interpretation at the same time. Often times, a student grasps an understanding of an artist's interpretation of a certain phrase, but when asked to technically articulate these specifics on the instrument, is unable to do so. At the expert level, all these skills and the attention needed for developing them have become automatic.

Comparison of different performances recorded on the Yamaha Disklavier offers students the opportunity to analyze, while slowing the tempo in playback and listening repeatedly. Using the Disklavier in conjunction with a sequencing program allows MIDI data to be displayed as a piano roll providing visual feedback for the student. Augmented visual feedback can have striking effects on the acquisition and improvement of technical skills. (7) Cognitive feedback can improve expressive skills of music performance. (8, 9) Pianists control only two factors--timing and intensity. However, many musicians, teachers and students often fail to recognize the significance of these factors. Author C. Palmer examined three aspects of timing in piano performance that are not explicitly notated in the score: chord asynchronies, rubato patterns and legato/staccato patterns. (10) Results suggest that pianists may distort timing more than other instrumentalists who also are able to manipulate pitch and timber.

The Technology

MIDI is a data interface designed to communicate musical messages. The Yamaha Disklavier piano, used in the study discussed later, is an acoustic instrument equipped with optical laser sensors to measure the mechanical velocity of each key's hammer by registering the speed of its down-stroke. The pedals also are equipped with sensors.

The parameters are recorded digitally on a floppy disc for possible data analysis or playback. The playback feature ensures exact mechanical replication of the sounds produced in the original performance.

By utilizing music sequencing software to read the floppy disc, MIDI data can be displayed on a video screen as a scrolling piano roll, as shown in Figure 1. With respect to a display of the keyboard aligned vertically to the left, horizontal bars of various lengths indicate which keys are depressed, in what sequence and for how long. Some software, such as Emagic's Logic, displays the note bars in colors that vary from blue (soft) to red (loud) to represent dynamic levels.

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Feedback

How does the feedback process work? The Disklavier piano is connected to a computer via MIDI cables. Playing is recorded on the Disklavier or through the sequencing software program. Feedback on the performance is provided immediately to the student through playback on the Disklavier, while simultaneously viewing the piano roll on the computer screen. The role of the piano roll visual feedback in improving less-advanced students' understanding of rhythmic notation was examined more closely in two imitation approaches: 1) Disklavier/piano roll presentations of expressive models followed similarly by Disklavier/piano roll feedback of how well students' imitation attempts matched the models; 2) Disklavier-only presentation of models and aural feedback. …