### 2.2.127 Time_signature_engraver

Create a TimeSignature whenever `timeSignatureFraction` changes.

Properties (read)

> `implicitTimeSignatureVisibility` (vector)

>   break visibility for the default time signature.

> `timeSignatureFraction` (fraction, as pair)

>   A pair of numbers, signifying the time signature. For example, `'(4 . 4)` is a 4/4 time signature.

This engraver creates the following layout object(s):

TimeSignature.

`Time_signature_engraver` is part of the following context(s): DrumStaff, GregorianTranscriptionStaff, MensuralStaff, PetrucciStaff, RhythmicStaff, Staff and TabStaff.

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