A-B-A or Ternary form Composition or movement in three sections. The outer sections are identical or closely related, framing a contrasting middle section (A-B-A). Also called song form.
Fugue Composition or section that develops a musical idea (subject) in staggered entries (contrapuntal imitation). Think an elaborate round of “Row, Row, Row Your Boat.”
Minuet Elegant eighteenth-century dance in 3/4 time (meter) with a contrasting middle dance or section called a trio, followed by a return to the first section. Often used as the third movement in an eighteenth-century (Classical era) symphony.
Rondo A form using recurring refrains alternating with contrasting episodes. Often structured as A‑B‑A‑C‑A or A‑B‑A‑C‑A‑B‑A. Frequently used for last movements.
Scherzo (Literally “joke” in Italian) 1) Movement or piece in a light style. 2) A fast movement of a symphony, sonata, or quartet—sometimes light with rhythmic playfulness, other times fierce or dark. Like a minuet, a scherzo has a contrasting middle section called a trio, followed by a return to the opening section. It eventually replaced the minuet in nineteenth-century works.
Sonata form The most characteristic form of the eighteenth and nineteenth centuries, often used as the first movement of large-scale works like symphonies. Also used for stand-alone pieces or other movements of large-scale works. Musical ideas are presented (exposition), developed (development), and revisited (recapitulation). The form is often preceded by an introduction and followed by further musical comment (coda). Basic harmonic structure: home key (tonic), excursions to other keys, home key.
Ternary form See A-B-A form.
Theme and variations A self-contained musical unit (theme), followed by a series of modifications (variations) of the original material
—©Jane Vial Jaffe