Ad libitumIn music and other performing arts, the phrase ad libitum (ædˈlɪbᵻtəm; from Latin for 'at one's pleasure' or 'as you desire'), often shortened to "ad lib" (as an adjective or adverb) or "ad-lib" (as a verb or noun), refers to various forms of improvisation. The roughly synonymous phrase a bene placito ('in accordance with [one's] good pleasure') is less common but, in its Italian form a piacere, has entered the musical lingua franca (see below).
Ornament (music)In music, ornaments or embellishments are musical flourishes—typically, added notes—that are not essential to carry the overall line of the melody (or harmony), but serve instead to decorate or "ornament" that line (or harmony), provide added interest and variety, and give the performer the opportunity to add expressiveness to a song or piece. Many ornaments are performed as "fast notes" around a central, main note. There are many types of ornaments, ranging from the addition of a single, short grace note before a main note to the performance of a virtuosic and flamboyant trill.
ClavichordThe clavichord is a stringed rectangular keyboard instrument that was used largely in the Late Middle Ages, through the Renaissance, Baroque and Classical eras. Historically, it was mostly used as a practice instrument and as an aid to composition, not being loud enough for larger performances. The clavichord produces sound by striking brass or iron strings with small metal blades called tangents. Vibrations are transmitted through the bridge(s) to the soundboard.