tremolo

noun

1. 1

   A rapid repetition of the same note, or an alternation between two or more notes. It can also be intended to mean a rapid and repetitive variation in pitch for the duration of a note. It is notated by a strong diagonal bar across the note stem, or a detached bar for a set of notes (or stemless notes).

2. 2

   A variation in the volume of a note or a chord, evoking a tremor or quiver.

3. 3

   The device in an organ that produces a tremolo effect.