M.M.: Originally "Mälzel Metronome" but now metronome marking.

Maggiore: The major mode.

Major: "Greater". A term used to describe certain intervals (seconds, thirds,sixths and sevenths), chords and the Ionian Mode.

Major Chord: a triad composed of a root, a third, and a fifth.

Major Scale: A diatonic scale where the half-steps fall between the third and fourth, and the seventh. This scale is identical to the Ionian Mode.

Major Second: A second, or musical interval covering two adjacent staff positions, spanning two semitones.

Mannheim School: A Preclassical group of German symphonic composers whose style including extended crecendos (called steamrollers) and melodies that arpeggiated upward, (called rockets).

March: Music for marching, such as in a parade or procession.

Mixolydian Mode: A medieval mode whose scale pattern is that of playing G to G on the white keys of a piano.

Meter Signature: See time signature.

Metronome Marking: The tempo of a composition measured in beats per minute (BPM). The marking is usually found at the beginning of a composition.

Mode: A scale pattern consisting of set intervals of whole and half steps. The primary modes are Aeolian, Dorian, Ionian, Locrian, Lydian, Mixolydian, and Phrygian.

Modal: Pertaining to modes.

Modern: Music written in the 20th century, or contemporary music.

Modulation: 1. To change keys, the movement from one tonic center to another.

Monody: A solo or unison Song with accompaniement.

Monothematic: Music based upon a single theme.

Monophony: Music written in a single melodic line, as opposed to polyphony.

Morceau: "Morsel". A musical work or composition.

Mordent: An ornament consisting of a single alternation between a given pitch, and the one immeditatly below or above it--called an inverted mordent.

Motet: A choral composition, usually on a religious text.

Motif: A short musical idea, or melodic theme that runs through a piece.

Movement: A self-contained segment of a larger work. Found in works such as sonatas, symphonies, concertos, etc.

Musicology: The study of music and music history.

Music Drama: Opera, specifically that of Richard Wagner and his successors.

Musique Concrete: Music composed by manipulating aucoustically generated recorded real-world sounds.