Stacking of accidentals

If multiple accidentals are required for a chord in a single voice, or for notes in multiple voices at the same rhythmic position, they are stacked to the left of the chord in columns.

For chords with multiple accidentals, accidentals are generally stacked as follows:

  1. The highest accidental is inserted in the first column immediately to the left of the notes.

  2. The lowest accidental is added to the same column, provided that it does not collide with the first accidental.

  3. The remaining highest and lowest accidentals are alternated in successive columns located further left from the chord.

In Dorico Pro, additional rules help to produce a stack of accidentals that uses as few columns as possible. The following list contains some of the rules that are applied:

  • Columns closer to the notes contain more accidentals than columns further from the notes.

  • Accidentals on notes that are an octave apart are stacked in the same column. This also applies to accidentals that are a sixth or more apart, depending on the combination of accidentals.

  • Accidentals in the same column never collide. The minimum interval between accidentals that is required to prevent collisions depends on the types of accidentals.

  • Accidentals that are a second apart are arranged in adjacent columns, with the higher accidental in the right-hand column.

These rules minimize the amount of extra space that is required between successive notes or chords and ensure that accidentals appear as close as possible to the noteheads to which they apply. At the same time, they produce a contour that resembles a C-curve on the left-hand side of the chord.

Accidental stacking rules for dense chords

Dorico Pro uses special stacking calculations in dense chords with multiple accidentals to ensure legibility. Chords are considered dense when they have six or more accidentals within the span of an octave.

For dense chords, accidentals are stacked as follows:

  1. The highest accidental is inserted in the first column to the left of the notes.

  2. The next accidental on a note that is located at least a seventh below the highest note is stacked into the same column. This continues with the remaining notes until no more accidentals fit into the first column.

  3. Steps 1 and 2 are repeated for the following columns until all accidentals are stacked.

  4. The columns are grouped, interspersed, and re-stacked. This results in a stack with alternating accidentals, reminiscent of the way accidentals are arranged in a key signature.

By default for dense chords, Dorico Pro uses a lattice arrangement of accidentals rather than the usual zig-zag arrangement. In very dense chords, the lattice arrangement can be wider and require more columns.

Tip

You can customize the default settings for the stacking of accidentals project-wide in the Stacking section of the Accidentals page in Engraving Options. For example, you can allow accidentals to be stacked without interspersion, so that accidentals appear in a diagonal line sloping downwards to the left.