Ada source code for data structures for an internal representation of notated music.

The names of the internal music notation framework objects are closely modelled after MusicXML.

Because some identifiers were quite long, the were replaced with abbreviations: Identification became I11n, Direction_Type became Dir_Type.

Some of the values in the MusicXML DTDs could not be used as identifiers in Ada, either because they begin with a digit, like 16th, or because they are reserved words in Ada, like begin and end. All these were prefixed with N_ to legalize them.