LilyPond program-reference: 2.2.58 Measure_grouping_engraver

### 2.2.58 Measure_grouping_engraver

Create `MeasureGrouping` to indicate beat subdivision.

Properties (read)

> `beatLength` (moment)

>   The length of one beat in this time signature.

> `currentMusicalColumn` (layout object)

>   Grob that is X-parent to all non-breakable items (note heads, lyrics, etc.).

> `measurePosition` (moment)

>   How much of the current measure have we had. This can be set manually to create incomplete measures.

> `beatGrouping` (list)

>   A list of beatgroups, e.g., in 5/8 time `'(2 3)`.

This engraver creates the following layout object(s):

MeasureGrouping.

`Measure_grouping_engraver` is not part of any context.

#### Internals Reference