Element: direction-type

The accordion-registration type is use for accordion registration symbols. These are circular symbols divided horizontally into high, middle, and low sections that correspond to 4', 8', and 16' pipes. Each accordion-high, accordion-middle, and accordion-low element represents the presence of one or more dots in the registration diagram. An accordion-registration element needs to have at least one of the child elements present.

Brackets are combined with words in a variety of modern directions.  The line-type is solid by default.

The coda element is the visual indicator of a coda sign. A sound element is needed to guide playback applications reliably.

The damp element specifies a harp damping mark.

The damp-all element specifies a harp damping mark for all strings.

The dashes type represents dashes, used for instance with cresc. and dim. marks.

Dynamics can be associated either with a note or a general musical direction. To avoid inconsistencies between and amongst the letter abbreviations for dynamics (what is sf vs. sfz, standing alone or with a trailing dynamic that is not always piano), we use the actual letters as the names of these dynamic elements. The other-dynamics element allows other dynamic marks that are not covered here, but many of those should perhaps be included in a more general musical direction element. Dynamics elements may also be combined to create marks not covered by a single element, such as sfmp. These letter dynamic symbols are separated from crescendo, decrescendo, and wedge indications. Dynamic representation is inconsistent in scores. Many things are assumed by the composer and left out, such as returns to original dynamics. Systematic representations are quite complex: for example, Humdrum has at least 3 representation formats related to dynamics. The MusicXML format captures what is in the score, but does not try to be optimal for analysis or synthesis of dynamics.

The eyeglasses element specifies the eyeglasses symbol, common in commercial music.

The harp-pedals type is used to create harp pedal diagrams. The pedal-step and pedal-alter elements use the same values as the step and alter elements. For easiest reading, the pedal-tuning elements should follow standard harp pedal order, with pedal-step values of D, C, B, E, F, G, and A.

The metronome type represents metronome marks and other metric relationships. The beat-unit group and per-minute element specify regular metronome marks. The metronome-note and metronome-relation elements allow for the specification of more complicated metric relationships, such as swing tempo marks where two eighths are equated to a quarter note / eighth note triplet.

The octave shift type indicates where notes are shifted up or down from their true pitched values because of printing difficulty. Thus a treble clef line noted with 8va will be indicated with an octave-shift down from the pitch data indicated in the notes.

The pedal type represents piano pedal marks. The change and continue types are used when the line attribute is yes. The change type indicates a pedal lift and retake indicated with an inverted V marking. The continue type allows more precise formatting across system breaks and for more complex pedaling lines. The alignment attributes are ignored if the line attribute is yes.

The percussion element is used to define percussion pictogram symbols. Definitions for these symbols can be found in Kurt Stone's "Music Notation in the Twentieth Century" on pages 206-212 and 223. Some values are added to these based on how usage has evolved in the 30 years since Stone's book was published.

The principal-voice element represents principal and secondary voices in a score, either for analysis or for square bracket symbols that appear in a score. The content of the principal-voice element is used for analysis and may be any text value. When used for analysis separate from any printed score markings, the symbol attribute should be set to "none".

The rehearsal type specifies a rehearsal mark. Language is Italian ("it") by default. Enclosure is square by default. Left justification is assumed if not specified.

Scordatura string tunings are represented by a series of accord elements, similar to the staff-tuning elements. Strings are numbered from high to low.

The segno element is the visual indicator of a segno sign. A sound element is needed to guide playback applications reliably.

The string-mute type represents string mute on and mute off symbols.

The wedge type represents crescendo and diminuendo wedge symbols. The type attribute is crescendo for the start of a wedge that is closed at the left side, and diminuendo for the start of a wedge that is closed on the right side. Spread values are measured in tenths; those at the start of a crescendo wedge or end of a diminuendo wedge are ignored. The niente attribute is yes if a circle appears at the point of the wedge, indicating a crescendo from nothing or diminuendo to nothing. It is no by default, and used only when the type is crescendo, or the type is stop for a wedge that began with a diminuendo type. The line-type is solid by default.