How to add accidentals and double accidentals in Flat
Last updated September 23, 2026
An accidental in Flat is a sign that raises or lowers a note outside the key signature. Flat writes sharps, flats, and naturals, cycles through double sharps, double flats, and courtesy accidentals from the same button, and can prepare an accidental so it applies to the next note you write.
Where are the accidental buttons?
The accidentals sit in the compact strip above the left panel, alongside the duration buttons, so they stay available whichever tab of the left panel is open. Each one also has a keyboard shortcut, which keeps your hands on the keyboard while you write a chromatic passage.
| Accidental | Keyboard shortcut |
|---|---|
| Natural | 0 |
| Sharp | = |
| Flat | - |
How do I add an accidental to a note?
Click the note you want to alter, then click the accidental you need - sharp, flat, or natural - in the strip above the left panel. Flat writes the sign in front of the notehead and adjusts playback to match. Clicking the natural button on an altered note removes the accidental.
How do I write a double accidental or a courtesy accidental?
Click the same accidental button several times on the same note. Flat cycles through adding the accidental, adding a double sharp or double flat, removing it, and adding a courtesy accidental - the reminder sign printed in brackets or without brackets to confirm a pitch to the performer.
Can I prepare an accidental before I write the note?
Yes. If your cursor is on a rest rather than on a note, clicking an accidental prepares it instead of applying it: the next note you write is created with that accidental already in place. This is quicker than writing a note and altering it afterwards when you are entering a chromatic line.
Frequently asked questions
How do I remove an accidental from a note?
Apply the natural sign to it, or keep clicking the accidental you added until the cycle returns to no accidental. Both routes bring the note back to the pitch implied by the key signature, and Flat updates the playback at the same time so what you hear matches what is written.
What is a courtesy accidental and when should I use one?
A courtesy accidental is a reminder sign that confirms a pitch without changing it, typically after an accidental earlier in the bar or in the previous bar. Flat produces one by cycling the same accidental button on a note, so you can add reminders wherever a performer might hesitate.
Can I write quarter-tone accidentals in Flat?
Yes, but they are a separate premium feature and must be enabled for the part first. Once enabled, four quarter accidentals become available alongside the usual ones. See how to use quarter-tones for enabling them and writing them into a score.