Quarter note/rest:  A note/rest one half the length of a half note and one quarter the length of a whole note.

Quartet:  A piece for four instruments or voices. Four performers.

Quasi:  Almost. Used with other terms, e.g. quasi madrigal, almost or as if a madrigal.

Quintet:  A piece for five instruments or voices. Five performers.

Rallentando, rall:  Gradually slower. Synonymous with ritardando.

Rapide:  Rapidly.

Re:  In solmization, the second degree of the major scale.

Recital:  A performance by one or more performers.

Refrain:  A short section of repeated material which occurs at the end of each stanza.

Relative major and minor scales:  Major and minor scales which have the same key signature.

Repeat:  The repetition of a section or a composition as indicated by particular signs.

Resonance:  Reinforcement and intensification of sound by vibrations.

Rest:  A symbol used to denote silence.

Rhapsody:  A free style instrumental piece characterized by dramatic changes in mood.

Rhythm:  The term which denotes the organization of sound in time; the temporal quality of sound.

Rinforzando:  A reinforced accent.

Risoluto:  Resolute.

Rit., Ritardando:  Gradually becoming slower

Ritardando, rit:  Gradually slower. Synonymous with rallentando.

Ritenuto:  Immediate reduction in tempo.

Ritmico:  Rhythmically.

Roll:  On percussion instruments, a sticking technique consisting of a rapid succession of notes: