Red Notes: In medieval music, notes that were colored red on the page in order to distinguish differences in rhythm or octave transposition for specific notes. They were also used to show differences in a cantus firmus from the original.
Renaissance: "Rebirth." The era from the mid-15th century to the end of the 16th century. The music was charactarized by the use of freer forms, and a progression from modes toward major and minor scales, and harmony.
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.
Ritardando, rit: Gradually slower. Same as rallentando.
Ritenuto: Immediate reduction in tempo.
Roll: On percussion instruments, a sticking technique consisting of a rapid succession of notes.
Root position: The arrangement of a chord in which the root is in the lowest voice.
Round: Similar to a canon, a song in which two or more parts having the same melody, starting at different points. The parts may be repeated as desired.
Rubato: Denotes flexibility of tempo to assist in achieving expressiveness.
Rudiments: On percussion instruments, the basic sticking patterns.
Run: A rapid scale passage.
Rustico: Rustic; rural; pastoral.