### 1.1.25 EventChord

Explicitly entered chords.

When iterated, `elements` are converted to events at the current timestep, followed by any `articulations`. Per-chord postevents attached by the parser just follow any rhythmic events in `elements` instead of utilizing `articulations`.

An unexpanded chord repetition ‘`q`’ is recognizable by having its duration stored in `duration`.

Properties:

> `iterator-ctor` (procedure):

>   `ly:event-chord-iterator::constructor`

>   Function to construct a `music-event-iterator` object for this music.

> `length-callback` (procedure):

>   `ly:music-sequence::event-chord-length-callback`

>   How to compute the duration of this music. This property can only be defined as initializer in ‘`scm/define-music-types.scm`’.

> `name` (symbol):

>   `'EventChord`

>   Name of this music object.

> `to-relative-callback` (procedure):

>   `ly:music-sequence::event-chord-relative-callback`

>   How to transform a piece of music to relative pitches.

> `types` (list):

>   `'(general-music event-chord simultaneous-music)`

>   The types of this music object; determines by what engraver this music expression is processed.

#### Internals Reference v2.18.2 (稳定分支).