Music 253

Old front page for Music 253: http://www.ccarh.org/courses/253

What is Musical Information?

Musical information (also called musical informatics) is a body of information used to specify the content of a musical work. There is no single method of representing musical content. Many digital systems of musical information have evolved since the 1950s, when the earliest efforts to generate music by computer were made. In the present day several branches of musical informatics exist. These support applications concerned mainly with sound, mainly with graphical notation, or mainly with analysis.

Musical representation generally refers to a broader body of knowledge with a longer history, spanning both digital and non-digital methods of describing the nature and content of musical material. The syllables do-re-mi (identifying the first three notes of an ascending scale) can be said to represent the beginning of a scale. Unlike graphical notation, which indicates exact pitch, this representation scheme is moveable. It pertains to the first three notes of any ascending scale, irrespective of its pitch.

The Pitch Component

Two kinds of information--pitch and duration--are pre-eminent, for without pitch there is no sound, but pitch without duration has no substance. Trained musicians develop a very refined sense of pitch. Systems for representing pitch span a wide range of levels of specificity. Simple discrimination between ascending and descending pitch movements meet the needs of many young children, while elaborate systems of microtonality exist in some cultures.

There are many graduated continua--diatonic, chromatic, and enharmonic scales--for describing pitch. Absolute measurements such as frequency can be used to describe pitch, but for the purposes of notation and analysis other nomenclature is used to relate a given pitch to its particular musical context.

The Duration Component

Duration has contrasting features: how long a single note lasts is entirely relative to the rhythmic context in which it exists. Prior to the development of the Musical Instrumental Digital Interface (MIDI) in the 1980s the metronome was the only widely used tool to calibrate the pace of music (its tempo). MIDI provides a method of calibration that facilitates capturing very slight differences of the execution in order to "record" performance in a temporally precise way. In most schemes of music representation values are far less precise. Recent psychological studies have demonstrated that while human expectations of pitch are precise, a single piece of music accommodates widely discrepant executions of rhythm. People can be conditioned to perform music in a rote manner, with little variation from one performance to another, but deviation from a regular beat is normal.

Other Dimensions of Musical Information

Many other dimensions of musical information exist. Gestural information registers the things a performer may do to execute a work. These could include articulation marks for string instruments; finger numbers and pedal marks for piano playing; breath marks for singers and wind players; heel-toe indicators for organists, and so forth. Some attributes of music that are commonly discussed, such as accent, are implied by notation but are not actually present in the fabric of the musical work. They occur only in its execution.

Domains of Musical Information

Applications of musical information (or data) are said to exist in various domains. The notation domain requires extensive information about placement on a page or screen. The sound domain requires information about musical timbre. In the notation domain a dynamic change may be represented by a single symbol, but in the sound domain a dynamic change will affect the parameters of a series of consecutive notes.

The logical domain is slightly elusive, for it refers to the parameters required to fully represent a musical work minus those that indicate placement, position, or sound quality--attributes specific to graphical display for sound rendition.

Systems of Musical Information

In the realm of computer applications, the handling of musical data is more complex than that of text for two primary reasons: (1) most music is polyphonic (more than one voice or part is sounding at one time) and (2) there is no default format for musical data. This absence owes largely to the enormous range of musical styles and methods of production that exist throughout the world. No one scheme is favorable to situations.

Domain differences favor domain-specific approaches: it is more practical to develop and employ code that is task- or repertory-specific than to disentangle large numbers of variables addressing multiple domains in a "complete" representation system.

References

1. Musical symbol list (incomplete): http://en.wikipedia.org/wiki/List_of_musical_symbols