### 3.1.79 NoteHead

NoteHead objects are created by: Completion_heads_engraver, Drum_notes_engraver and Note_heads_engraver.

Standard settings:

> `duration-log` (integer):

>   `note-head::calc-duration-log`

>   The 2-log of the note head duration, i.e., `0` = whole note, `1` = half note, etc.

> `extra-spacing-height` (pair of numbers):

>   `ly:note-head::include-ledger-line-height`

>   In the horizontal spacing problem, we increase the height of each item by this amount (by adding the ‘car’ to the bottom of the item and adding the ‘cdr’ to the top of the item). In order to make a grob infinitely high (to prevent the horizontal spacing problem from placing any other grobs above or below this grob), set this to `(-inf.0 . +inf.0)`.

> `glyph-name` (string):

>   `note-head::calc-glyph-name`

>   The glyph name within the font.

>   In the context of (span) bar lines, glyph-name represents a processed form of `glyph`, where decisions about line breaking etc. are already taken.

> `stem-attachment` (pair of numbers):

>   `ly:note-head::calc-stem-attachment`

>   An `(x . y)` pair where the stem attaches to the notehead.

> `stencil` (stencil):

>   `ly:note-head::print`

>   The symbol to print.

> `X-offset` (number):

>   `ly:note-head::stem-x-shift`

>   The horizontal amount that this object is moved relative to its X-parent.

> `Y-extent` (pair of numbers):

>   `#<unpure-pure-container #<primitive-procedure ly:grob::stencil-height> >`

>   Extent (size) in the Y direction, measured in staff-space units, relative to object’s reference point.

> `Y-offset` (number):

>   `#<unpure-pure-container #<primitive-procedure ly:staff-symbol-referencer::callback> >`

>   The vertical amount that this object is moved relative to its Y-parent.

This object supports the following interface(s): font-interface, gregorian-ligature-interface, grob-interface, item-interface, ledgered-interface, ligature-head-interface, mensural-ligature-interface, note-head-interface, rhythmic-grob-interface, rhythmic-head-interface, staff-symbol-referencer-interface and vaticana-ligature-interface.

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