LilyPond Internals Reference: 1.1.63 PartialSet

### 1.1.63 `PartialSet`

Create an anacrusis or upbeat (partial measure).

Properties:

`iterator-ctor` (procedure):

  `ly:partial-iterator::constructor`

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

`length-callback` (procedure):

  `ly:music-sequence::cumulative-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):

  `'PartialSet`

  Name of this music object.

`types` (list):

      '(partial-set)

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

#### LilyPond – Internals Reference v2.24.4 (stable-branch).