Unfigured bass, less commonly known as under-figured bass, is a kind of musical notation used during the Baroque music era in Western Classical music (ca. 1600–1750) in which a basso continuo performer playing a chordal instrument (e.g., harpsichord, organ, or lute) improvises a chordal accompaniment from a notated bass line which lacks the guidance of figures indicating which harmonies should be played above the bass note (see figured bass).[1] Figured bass parts have numbers or accidentals above the bass line which indicate which intervals above the bass should be played in the chord. However, not all basso continuo parts from the Baroque period were figured.