Chorale - Hymn-like song, characterized by blocked chords.
Disjunct - The term used to describe intervals larger than a second; the opposite of conjunct.
Fourth - The fourth degree of the diatonic scale. Also, the interval formed by a given tone and the fourth tone above or below it, e.g. c up to f; c down to g. Intervals of the fourth may be perfect, diminished, or augmented.
Metronome - Invented by Maelzel in 1816, the instrument is used to indicate the exact tempo of a composition. An indication such as M.M. 60 indicates that the pendulum, with a weight at the bottom, makes 60 beats per minute. A slider is moved up and down the pendulum to decrease and increase the tempo. M.M. = 80 means that the time value of a quarter note is the equivalent of one pendulum beat when the slider is set at 80.
Overture - The introductory music for an opera, oratorio or ballet. A concert overture is an independent work.