SGML: SMDL Overview

SGML: SMDL Overview

The following "overview" of SMDL is extracted from the July 1995 DIS of ISO/IEC 10743 as released by the editors for review on the Internet. See the PostScript and PDF versions available on the WG8 FTP server: (245653 bytes), or (257383 bytes). Alternate access to the [July] DIS: See also in this database the main bibliographic entry, or the newly-created SMDL entry.

Scope and Field of Application

This International Standard defines an architecture for the representation of music information, either alone or in conjunction with text, graphics, or other information needed for publishing or business purposes. Multimedia time sequencing information is also supported. The architecture is known as the "Standard Music Description Language", or "SMDL".

SMDL is a "HyTime" application; it conforms to International Standard ISO/IEC 10744 - Hypermedia / Time-based Structuring Language ("HyTime"). Specifically, SMDL is a "derived architecture" derived from the HyTime architecture, and SMDL is expressed in this International Standard in a manner which conforms to HyTime's specifications for the expression of architectures (also known as "meta-DTDs") and derived architectures.

SMDL is an SGML application conforming to International Standard ISO 8879 - Standard Generalized Markup Language.

1.1 Scope

SMDL is capable of representing many (but not all) genres of music, and most (but not necessarily all) instances of works in those genres. The aim of SMDL is primarily to permit the application neutral interchange of all such music as can reasonably be expressed in common practice music notation, i.e. the written notation commonly used for Western-style art music, dance music, and commercial music. However, music represented in SMDL need not actually have ever been expressed in common Western music notation, or in any other particular notation. The use of SMDL as an abstract music representation does not preclude the rendition of special symbols or other particular notational or performance practices, in either visually or aurally perceivable source or formatted output materials.

By virtue of its total reliance on and compatibility with the HyTime International Standard, music represented in SMDL can include musically dependent or independent multimedia time sequences, such as slide show control tracks or automated lighting information. Combinations of musical and non-musical events, for example, in a dramatic production, are possible as well.

SMDL is designed for flexibility and extensibility. There are no technical prohibitions against the use of some components without the whole, or against the use of user-defined components in conjunction with standardized ones.

SMDL includes a conformance clause that identifies minimum and higher levels of support in terms of standardized architecture components and options for user extensions.

1.2 Field of Application

SMDL is designed for the transmission and storage of music and hypermedia information. It is optimized for completeness, flexibility, and ease of use. There has been some attention to human readability, principally for the benefit of applications implementers, as it is unlikely there will be much direct manual creation of SMDL documents. The architecture is not intended as a foundation for modern computer music composition, although, depending on the compositional and performance process, parts or all of it might be useful for some purposes in some works.

Typical original sources of works that can be represented in SMDL are printed scores, performances recorded in a manner that permits machine transcription, pieces that are already represented in a (non-standard) music description language, and composers using computer-based compositional and/or notational aids which have the capability of exporting the pieces as SMDL.

Multimedia information, such as digital audio recordings, can be associated and synchronized with music and described in SMDL. The multimedia elements will have their own notations and encodings. Standards for such notations and encodings are outside the scope of this International Standard. Examples of mixed music and multimedia applications include: business presentations containing synthesized music, sequenced live sound excerpts, slide change signals, and recorded or synthesized speech; and dramatic productions containing music, lighting control, and digitally recorded sound effects.