Breaking.

A term used in England from the 16th century to the 18th to describe the ornamentation of a pre-existing melodic line by substituting groups of short notes for most of the longer notes, especially in improvised performance. Christopher Simpson (The Division-Violinist, 1659) refers particularly to ‘Breaking the Ground’ as ‘dividing its Notes into more diminute notes’. He also refers to ‘the Breaking of a Note’ as a thing ‘very necessary (sometimes) in Composition … to make a smooth or sweeten the roughness of a Leap, by a graduall Transition to the Note next following [ie. by adding passing notes and other embellishments]’ (Compendium of Practical Musick, 1667). (See also Division and Improvisation, §II, 1(ii).)