### 2.2.2 Ambitus_engraver

Create an ambitus.

Properties (read)

> `keySignature` (list)

>   The current key signature. This is an alist containing `(step . alter)` or `((octave . step) . alter)`, where step is a number in the range 0 to 6 and alter a fraction, denoting alteration. For alterations, use symbols, e.g. `keySignature = #`((6 . ,FLAT))`.

> `middleCClefPosition` (number)

>   The position of the middle C, as determined only by the clef. This can be calculated by looking at `clefPosition` and `clefGlyph`.

> `middleCOffset` (number)

>   The offset of middle C from the position given by `middleCClefPosition` This is used for ottava brackets.

This engraver creates the following layout object(s):

AccidentalPlacement, Ambitus, AmbitusAccidental, AmbitusLine and AmbitusNoteHead.

`Ambitus_engraver` is not part of any context.

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