Quadrat
(German) Natural

Quadrille
(French) A 19th century ballroom dance for 4+ couples, usually based on popular music of the day

Quadruple meter
Four beats per measure

Quality
In reference to a tone, the difference in character, for example, a specific tone played on the piano vs on the violin

Quantity
In reference to a tone, the duration a note is played, not volume

Quart de soupir
(French) Quarter note

Quasi
(Latin) Almost, same, as if

Quatuor
(French) Quartet

Quaver
(British) Eighth note

Quena
A type of flute made from bamboo originating from the Andes Mountains, South America

Queue
(French) stem

Quintet
Piece for 5 players

Quarter-note
A note that gets one-fourth the beat of a whole note

Quarter tone
Semi-tone that is half a half-step, uncommon in Western music

Quartet
A composition for 4 players