antiphon — in liturgical music (especially in the Roman Catholic singing of the Divine Office), a short phrase sung before and/or after a psalm or canticle. The antiphon can reinforce the meaning of the text, or it can draw out a distinctively Christian understanding from the Old Testament text being framed.
aria — a piece for accompanied solo voice that is part of a larger work (e.g., cantata, opera, etc.). Arias are often employed to convey emotional content and often include — unlike recitatives — repetition of words and phrases with musical elaboration.
basso continuo (abbr. as “continuo”)— literally, “continuous bass, ” this term designates an instrumental accompaniment, usually by a keyboard instrument, often paired with a double bass or a bassoon. Often referred to simply as “continuo,” this instrumental component of much 17th- and 18th-century music provides a harmonic framework within which other voices or instruments orient their melodic statements.
BWV — the abbreviation for the standard list or catalogue of all of Johann Sebastian Bach’s works.
canticle — a hymn used regularly within the liturgy and (often) with a text taken from the Bible. For example, in the Morning Prayer service, the canticles include Venite, exultemus Domino (“O come let us sing unto the Lord,” a text from Psalm 95), Benedictus es, Domine (“Blessed art thou, O Lord God of our fathers,” taken from the Apocryphal Song of the Three Young Men, verses 29-34), and Te Deum laudamus (“We praise thee, O God,” which is from a late 4th-century hymnal and often attributed to St. Ambrose). In Evening Prayer, the traditional canticles include the Magnificat (“My soul doth magnify the Lord,” the Virgin Mary’s song from St. Luke 1:46-55) and the Nunc dimittis (“Lord, lettest thou thy servant depart in peace,” the song of Simeon from St. Luke 2:29-32).
chorale — a metrical hymn tune common in Lutheran hymnody and in musical compositions that incorporate elements from the Lutheran musical tradition. Many cantatas by J. S. Bach and others often include final movements in which the chorale is sung in four-part harmony, but chorales melodies are often employed in more complex musical forms. For example, Felix Mendelssohn’s Symphony No. 5 is often called the ‘Reformation’ Symphony because he employed the chorale we know as “A Mighty Fortress” in its composition.
continuo — short for basso continuo
recitative — a piece for solo voice within a larger work, usually short, unadorned, and often directly advancing the “story line” of the work. Like chant, the rhythms of recitatives follow the speech patterns of spoken words much more closely than do arias.
responsory — a text used in the liturgy of the Mass, Morning Prayer, or Evening Prayer that is sung responsorially, that is, with a cantor or small group singing verses while the whole choir or congregation then respond with a refrain.
S.A.T.B. — an abbreviation indicating a piece that includes vocal parts for soprano, alto, tenor, and bass voices.
Sarum Use, or Sarum Rite
tone — a melodic formula used to chant a psalm or canticle. A guide to singing a tone is available here.