A cappella Choral music without instrumental accompaniment.
Cantus firmus Melody—often a Gregorian chant—used as the basis of a polyphonic composition.
Church modes Scales containing seven tones with an eighth tone duplicating the first an octave higher, but with different patterns of whole and half steps from major and minor scales; used in medieval, Renaissance, and twentieth-century music and in folk music.
Drone Long, sustained tone or tones accompanying a melody.
Gregorian chant Melodies set to sacred Latin texts, sung without accompaniment; was the official music of the Roman Catholic church.
Harp Plucked string instrument, consisting of strings stretched within a triangular frame. (https://caslabs.case.edu/medren/medieval-instruments/harp-medieval/)
Lute Plucked string instrument shaped like half a pear; used in Renaissance and baroque music. (https://caslabs.case.edu/medren/renaissance-instruments/lute-renaissance/
Mass Sacred choral composition made up of five sections: Kyrie, Gloria, Credo, Sanctus, and Agnus Dei.
Mass ordinary Roman Catholic church texts which remain the same from day to day throughout most of the year: Kyrie, Gloria, Credo, Sanctus, and Agnus Dei.
Monophonic texture Single melodic line without accompaniment.
Notation System of writing down music so that specific pitches and rhythms can be communicated.
Organ (pipe organ) Keyboard instrument with many sets of pipes controlled from two or more keyboards, including a pedal keyboard played by the organist's feet. The keys control valves from which air is blown across or through openings in the pipes. (The electric organ is an electronic instrument that is sometimes designed to imitate the sound of a pipe organ.) (https://caslabs.case.edu/medren/renaissance-instruments/organ-renaissance/)
Organum Medieval polyphony that consists of Gregorian chant and one or more additional melodic lines.
Polyphonic texture Performance of two or more melodic lines of relatively equal interest at the same time.