Musical Information (Music 253)

Musical Information: An Introduction

The title Musical Information: An Introduction has been in use at Stanford University since 1994 for the title of a course introducing a wide range of descriptions of musical content used in computer applications in music. Such applications fall into three main areas: (1) notation, (2) sound, and (3) data optimized for analytical use.

Encoding

When music is represented in some way that facilitates its manipulation in a computer application, we say that it is encoded. Semioticians have insisted in recognizing the difference between music and its representation by symbols. This distinction is infinitely useful in considerations of musical information. It parallels the common differentiation of sound and symbol in the analysis of poetry. Just as assonance is a sound-quality in the reading of a poem but depends on letter combinations in writing, so "forte" is a sound quality in music but depends on an "f" sign in a musical score. The sound and the letter "f" are not the same thing, but they are adjuncts to each other.

Divergent Practices and Needs

There is no ASCII code for music—no single method of describing it. This apparent absence flows from the fact that there is no best way to encode music. Most encoding systems are optimized for a single application area. Notational description requires a generous supply of spatial description; sound description requires a generous supply of timbral and articulatory information. Another tier of information inheres in needs specific to an instrument, a historical period, a particular culture, or some other fundamental variable.

All the world's music, from all times, presents a very broad array of divergences. In Western art music polyphony is highly evolved and there generates the need for both written scores and very extensive descriptions of pitch. In music of the Indian subcontinent, melodic extenuation is highly evolved but written scores were long considered undesirable. Mnemonic means of reminded players how to proceed can be encoded, but the spontaneity of a performance cannot. In some indigenous African cultures and in some branches of jazz rhythmic modes play a fundamental role. Aurally oriented musical cultures such as these have generated a relatively slight codification, other than through oral tradition as governed by the best practitioners.

The Notation Domain

What information does a musical score contain? Musical notation as it is used in Western art music contains centuries of refinements, accretions, and responses to changing musical style. Such music is heavily prescribed: composers and arrangers attempt to tell musicians exactly what tones to use (pitch) and exactly for how long to play each one (duration).

Although notation seems cumbersome to those who are accustomed to improvised repertories, it is in many ways one of the most ingenious writing systems ever developed. A single note can tell a performer several things through a single symbol. The synthesis of multiple kinds of information in a single symbol that is so convenient for the performer can be ab obstacle to the user of encoded musical information because the several strands of information graphically combined must be separated into their various spheres--pitch and duration (mandatory); also inflection, loudness, articulation, and lyrics (optional).

Uncommon Repertories

Although CMN covers a large quantity of music, it covers best music composed in European and America between the late seventeenth- and early twentieth-centuries. The practice of writing music has a much longer history, one of a millennium or more. Many compositions of the past half-century, reflecting expanding notions of what music is, greatly exceed the limits of CMN. Commercial notation products generally limit their purview to CMN, supplemented by features often required in popular music, e.g. chordal tablature for guitars.