LilyPond Internals Reference: 3.2.111 system-interface

### 3.2.111 system-interface

This is the top-level object: Each object in a score ultimately has a `System` object as its X and Y parent.

#### User settable properties:

> `labels` (list)

>   List of labels (symbols) placed on a column.

> `skyline-horizontal-padding` (number)

>   For determining the vertical distance between two staves, it is possible to have a configuration which would result in a tight interleaving of grobs from the top staff and the bottom staff. The larger this parameter is, the farther apart the staves are placed in such a configuration.

#### Internal properties:

> `all-elements` (array of grobs)

>   An array of all grobs in this line. Its function is to protect objects from being garbage collected.

> `columns` (array of grobs)

>   An array of grobs, typically containing `PaperColumn` or `NoteColumn` objects.

> `pure-Y-extent` (pair of numbers)

>   The estimated height of a system.

This grob interface is used in the following graphical object(s): System.

#### Internals Reference