5.2.2 Properties found in interfaces (LilyPond Learning Manual)

#### 5.2.2 Properties found in interfaces

Suppose now that we wish to print the lyrics in italics. What form of `\override` command do we need to do this? We first look in the IR page listing ‘All layout objects’, as before, and look for an object that might control lyrics. We find `LyricText`, which looks right. Clicking on this shows the settable properties for lyric text. These include the `font-series` and `font-size`, but nothing that might give an italic shape. This is because the shape property is one that is common to all font objects, so, rather than including it in every layout object, it is grouped together with other similar common properties and placed in an Interface, the `font-interface`.

So now we need to learn how to find the properties of interfaces, and to discover what objects use these interface properties.

Look again at the IR page that describes `LyricText`. At the bottom of the page is a list of clickable interfaces that `LyricText` supports. The list has several items, including `font-interface`. Clicking on this brings up the properties associated with this interface, which are also properties of all the objects which support it, including `LyricText`.

Now we see all the user-settable properties which control fonts, including ‘`font-shape` (symbol)’. The value in parentheses gives the variable type expected by the property; here it is a (Scheme) symbol. The IR also documents the possible values, which are `upright`, `italics`, or `slanted`.

You will notice that `font-series` and `font-size` are also listed there. This immediately raises the question: Why are the common font properties `font-series` and `font-size` listed under `LyricText` as well as under the interface `font-interface` but `font-shape` is not? The answer is that `font-series` and `font-size` are changed from their global default values when a `LyricText` object is created, but `font-shape` is not. The entries in `LyricText` then tell you the values for those two properties which apply to `LyricText`. Other objects which support `font-interface` will set these properties differently when they are created.

Let’s see if we can now construct the `\override` command to change the lyrics to italics. The object is `LyricText`, the property is `font-shape` and the value is `italic`. As before, we’ll omit the context.

As an aside, although it is an important one, note that some properties take values that are symbols, like `italic`, and must be preceded by an apostrophe, ‘`'`’. Symbols are then read internally by LilyPond. Note the distinction from arbitrary text strings, which would appear as `"a text string"`; for more details about symbols and strings, see Scheme tutorial.

So we see that the `\override` command needed to print the lyrics in italics is:

    \override LyricText.font-shape = #'italic

This should be placed just in front of the lyrics we wish to affect, like so:

>     {
>       \key es \major
>       \time 6/8
>       \relative {
>         r4 bes'8 bes[( g]) g |
>         g8[( es]) es d[( f]) as |
>         as8 g
>       }
>       \addlyrics {
>         \override LyricText.font-shape = #'italic
>         The man who | feels love's sweet e -- | mo -- tion
>       }
>     }

and the lyrics are all printed in italics.

Note: In lyrics, always leave whitespace between the final syllable and the terminating brace.

#### See also

Extending: Scheme tutorial.

#### LilyPond Learning Manual v2.26.0 (stable-branch).

- 1 Installing
  - 1.1 Graphical setup
  - 1.2 Command line setup
- 2 Tutorial
  - 2.1 Compiling a file
  - 2.2 How to write input files
    - 2.2.1 Input characters
    - 2.2.2 Simple notation
      - Pitches
      - Durations (rhythms)
      - Rests
      - Time signature
      - Tempo marks
      - Clef
      - All together
    - 2.2.3 Working on input files
  - 2.3 Dealing with errors
  - 2.4 How to read the manuals
    - 2.4.1 Omitted material
    - 2.4.2 Clickable examples
    - 2.4.3 Overview of manuals
- 3 Common notation
  - 3.1 Single-staff notation
    - 3.1.1 Bar lines and bar checks
      - Bar lines
      - Bar checks
    - 3.1.2 Pitches and key signatures
      - Pitch alterations
      - Key signatures
      - Warning: key signatures and pitches
    - 3.1.3 Ties and slurs
      - Ties
      - Slurs
      - Phrasing slurs
      - Warnings: slurs vs. ties
    - 3.1.4 Articulations and dynamics
      - Articulations
      - Fingerings
      - Dynamics
    - 3.1.5 Adding text
    - 3.1.6 Automatic and manual beams
    - 3.1.7 Advanced rhythmic commands
      - Partial measure
      - Tuplets
      - Grace notes
  - 3.2 Multiple notes at once
    - 3.2.1 Music expressions explained
      - Analogy: mathematical expressions
      - Simultaneous music expressions: multiple staves
      - Simultaneous music expressions: single-staff
    - 3.2.2 Multiple staves
    - 3.2.3 Staff groups
    - 3.2.4 Combining notes into chords
    - 3.2.5 Single-staff polyphony
  - 3.3 Songs
    - 3.3.1 Setting simple songs
    - 3.3.2 Aligning lyrics to a melody
    - 3.3.3 Lyrics to multiple staves
  - 3.4 Final touches
    - 3.4.1 Organizing pieces with variables
    - 3.4.2 Adding titles
    - 3.4.3 Absolute note names
    - 3.4.4 After the tutorial
- 4 Fundamental concepts
  - 4.1 How LilyPond input files work
    - 4.1.1 Introduction to the LilyPond file structure
    - 4.1.2 A score is a (single) compound musical expression
    - 4.1.3 Nesting music expressions
    - 4.1.4 Structure of a note entry
    - 4.1.5 On the un-nestedness of brackets and ties
  - 4.2 Voices contain music
    - 4.2.1 I’m hearing voices
    - 4.2.2 Explicitly instantiating voices
    - 4.2.3 Voices and vocals
  - 4.3 Contexts and engravers
    - 4.3.1 Contexts explained
    - 4.3.2 Creating contexts
    - 4.3.3 Engravers explained
    - 4.3.4 Modifying context properties
    - 4.3.5 Adding and removing engravers
  - 4.4 Extending the templates
    - 4.4.1 Soprano and cello
    - 4.4.2 Four-part SATB vocal score
    - 4.4.3 Building a score from scratch
    - 4.4.4 Saving typing with variables and functions
    - 4.4.5 Scores and parts
- 5 Tweaking output
  - 5.1 Tweaking basics
    - 5.1.1 Objects and interfaces
    - 5.1.2 Naming conventions of objects and properties
    - 5.1.3 Tweaking methods
      - The `\override` command
      - The `\revert` command
      - The `\once` prefix
      - The `\tweak` and `\offset` commands
      - The `\single` prefix
  - 5.2 The Internals Reference manual
    - 5.2.1 Properties of layout objects
    - 5.2.2 Properties found in interfaces
    - 5.2.3 Types of properties
  - 5.3 Appearance of objects
    - 5.3.1 Visibility and color of objects
      - The `stencil` property
      - The `break-visibility` property
      - The `transparent` property
      - The `color` property
    - 5.3.2 Size of objects
    - 5.3.3 Length and thickness of objects
  - 5.4 Offsets and alignments
  - 5.5 Placement of objects
    - 5.5.1 Automatic behavior
    - 5.5.2 Within-staff objects
      - The `direction` property
      - Fingering
    - 5.5.3 Outside-staff objects
      - The `outside-staff-priority` property
      - The `\textLengthOn` command
      - Dynamics placement
      - Grob sizing
  - 5.6 Vertical spacing
  - 5.7 Collisions of objects
    - 5.7.1 Moving objects
    - 5.7.2 Fixing overlapping notation
      - The `padding` property
      - The `right-padding` property
      - The `staff-padding` property
      - The `self-alignment-X` property
      - The `staff-position` property
      - The `extra-offset` property
      - The `positions` property
      - The `force-hshift` property
    - 5.7.3 Real music example
  - 5.8 Further tweaking
    - 5.8.1 Other uses for tweaks
      - Tying notes across voices
      - Simulating a fermata in MIDI
    - 5.8.2 Using variables for layout adjustments
    - 5.8.3 Style sheets
    - 5.8.4 Other sources of information
    - 5.8.5 Advanced tweaks with Scheme
- Appendix A Templates
  - A.1 Built-in templates
    - A.1.1 SATB template
    - A.1.2 SSAATTBB template
  - A.2 Single staff templates
    - A.2.1 Notes only
    - A.2.2 Notes and lyrics
    - A.2.3 Notes and chords
    - A.2.4 Notes, lyrics, and chords
  - A.3 Piano templates
    - A.3.1 Solo piano
    - A.3.2 Piano and melody with lyrics
    - A.3.3 Piano-centered lyrics
  - A.4 String quartet templates
    - A.4.1 String quartet
    - A.4.2 String quartet parts
  - A.5 Vocal ensembles templates
    - A.5.1 SATB vocal score
    - A.5.2 SATB vocal score and automatic piano reduction
    - A.5.3 SATB with aligned contexts
    - A.5.4 SATB on four staves
    - A.5.5 Solo verse and two-part refrain
    - A.5.6 Hymn tunes
    - A.5.7 Psalms
  - A.6 Orchestral templates
    - A.6.1 Orchestra, choir and piano
  - A.7 Ancient notation templates
    - A.7.1 Transcription of mensural music
    - A.7.2 Gregorian transcription template
  - A.8 Other templates
    - A.8.1 Jazz combo
- Appendix B GNU Free Documentation License
- Appendix C Index