A capriccio
A capriccio (Italian: "following one's fancy") is a tempo marking indicating a free and approach to the tempo (and possibly the style) of the piece. This marking will usually modify another, such as "lento a capriccio", often used in the Hungarian Rhapsodies of Franz Liszt. Perhaps the most famous piece to use the term is Ludwig van Beethoven's "Rondò a capriccio" (Op. 129), better known as "Rage Over a Lost Penny".