Accidental (music) felt it was obvious that the accidental should continue. The older practice continued in use well into the 18th century by many composers, notably Johann Sebastian Bach. The newer convention did not achieve general currency until early in the 19th century. Accidental (music) In music, an accidental is a note of a pitch (or pitch class) that is not a member of the scale or mode indicated by the most recently applied key signature. In musical notation, the sharp (), flat (), and natural () symbols, among others, mark such notes—and those symbols are also called accidentals. In the measure
Key signature the signature. In the major key with four flats (B E A D), for example, the penultimate flat is A, indicating a key of A major. In this case each new scale starts a fifth "below" (or a fourth above) the previous one. A key signature is not the same as a key; key signatures are merely notational devices. They are convenient principally for diatonic or tonal music. The key signature defines the diatonic scale that a piece of music uses without the need for accidentals. Most scales require that some notes be consistently sharped or flatted. For example, the