accidental

—accidentally, adv. —accidentalness, accidentality, n.

/ak'si den"tl/, adj.

1. happening by chance or accident; not planned; unexpected: an accidental meeting.

2. nonessential; incidental; subsidiary: accidental benefits.

3. Music. relating to or indicating sharps, flats, or naturals.

n.

4. a nonessential or subsidiary circumstance, characteristic, or feature.

5. Music. a sign placed before a note indicating a chromatic alteration of its pitch.

[1350-1400; ME < ML accidentalis. See ACCIDENT, -AL¹]

Syn. 1. unintentional, unforeseen. ACCIDENTAL, CASUAL, FORTUITOUS all describe something outside the usual course of events. ACCIDENTAL implies occurring unexpectedly or by chance: an accidental blow. CASUAL describes a passing event of slight importance: a casual reference. FORTUITOUS is applied to events occurring without known cause, often of a fortunate or favorable nature: a fortuitous shower of meteors. It often also implies good luck or good fortune: a fortuitous choice leading to rapid advancement.

Ant. 1. planned, contrived.

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▪ music

      in music, sign placed immediately to the left of (or above) a note to show that the note must be changed in pitch. A sharp (♯) raises a note by a semitone; a flat (♭) lowers it by a semitone; a natural (♮) restores it to the original pitch. Double sharps (×) and double flats (♭♭) indicate that the note is raised or lowered by two semitones. Sharps or flats that are placed at the beginning of a musical staff, called a key signature, indicate the tonality, or key, of the music and are not considered accidentals.

      Accidentals were first applied to the note B, by about the 10th century. To fulfill certain theoretical and aesthetic rules, B was sometimes flatted and, later, F was sometimes sharped. At first there was no sign for a natural; a sharp cancelled a flat, a flat cancelled a sharp. By the late Renaissance, E♭, A♭, and C♯ were fairly common. Accidentals applied to all notes became increasingly common in music of subsequent periods. In common modern practice, an accidental carries through the measure in which it occurs.

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