LilyPond Notation Reference: 5.3.3 The \override command

### 5.3.3 The `\override` command

There is a special type of context property: the grob description. Grob descriptions are named in `StudlyCaps` (starting with capital letters). They contain the ‘default settings’ for a particular kind of grob as an association list. See ‘`scm/define-grobs.scm`’ to see the settings for each grob description. Grob descriptions are modified with `\override`.

The syntax for the `\override` command is

>     \override [context.]GrobName.property = #value

For example, we can increase the thickness of a note stem by overriding the `thickness` property of the `Stem` object:

>     c''4 c''
>     \override Voice.Stem.thickness = #3.0
>     c''4 c''

If no context is specified in an `\override`, the bottom context is used:

>     \override Staff.Stem.thickness = #3.0
>     <<
>       \relative {
>         e''4 e
>         \override Stem.thickness = #0.5
>         e4 e
>       } \\
>       \relative {
>         c''4 c c c
>       }
>     >>

Some tweakable options are called ‘subproperties’ and reside inside properties. To tweak those, use commands in the form

>     \override Stem.details.beamed-lengths = #'(4 4 3)

or to modify the ends of spanners, use a form like these

>     \override TextSpanner.bound-details.left.text = "left text"
>     \override TextSpanner.bound-details.right.text = "right text"

The effects of `\override` can be undone by `\revert`.

The syntax for the `\revert` command is

>     \revert [context.]GrobName.property

For example,

>     \relative {
>       c''4
>       \override Voice.Stem.thickness = #3.0
>       c4 c
>       \revert Voice.Stem.thickness
>       c4
>     }

The effects of `\override` and `\revert` apply to all grobs in the affected context from the current time forward:

>     <<
>       \relative {
>         e''4
>         \override Staff.Stem.thickness = #3.0
>         e4 e e
>       } \\
>       \relative {
>         c''4 c c
>         \revert Staff.Stem.thickness
>         c4
>       }
>     >>

`\once` can be used with `\override` or `\revert` to affect only the current time step:

>     <<
>       \relative c {
>         \override Stem.thickness = #3.0
>         e''4 e e e
>       } \\
>       \relative {
>         c''4
>         \once \override Stem.thickness = #3.0
>         c4 c c
>       }
>     >>

#### See also

Internals Reference: Backend

#### LilyPond — Notation Reference v2.22.2 (stable-branch).