Courtesy Accidental
A repeated accidental added as a reminder, not required by the rules
Related
A courtesy accidental, also called a cautionary accidental, is a sharp, flat or natural repeated as a reminder even though the rules do not require it.
It appears after a barline when the same note returns, when a pitch repeats in another octave, after a key-signature change, or when a part re-enters after a long rest. It does not change pitch; it guards against misreading.
Publishers differ: some add parentheses, some use a smaller sign, some rely on spacing alone. When you meet an extra accidental, ask whether it is only a reminder before treating it as a new inflection.
Sources
- 提示性临时记号的用法，参 The New Grove Dictionary of Music and Musicians, "Accidental"；本文为原创表述
Used for fact-checking only; all prose is original.