Altered unisons
Altered unisons occur when two or more notes of the same name in the same octave have different accidentals in the same chord, such as D♯ and D♭.
In Dorico Pro, this is notated with a split stem, which allows both notes to appear with their corresponding accidental directly beside them. A split stem is sometimes known as a cherry stalk or a tree.
You can also have altered unisons appear with a single stem, meaning noteheads appear directly beside each other, and the two accidentals are shown beside each other to the left of the chord.
If a chord contains notes a second interval apart and one of those notes has an altered unison, it is always shown with a split stem, regardless of your setting. This is to ensure clarity in clusters.
Example
Figure: A single stem altered unison |
Figure: A split stem altered unison |