Ad Libitum
The performer decides the details — this is not the same as carelessness
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Ad libitum is Latin for "at one's pleasure"; by the usual account it entered musical notation with Italian terminology, which is why it is often taken for Italian. What it hands the player is a right to decide: tempo, rhythm, ornament or texture are judged by the performer, while the page supplies only a frame.
It names a degree of freedom, not a speed. A Baroque prelude, a concerto cadenza and a jazz chart marked ad lib all give the choice away, yet that freedom is still bounded by style, harmony and the other players. The common mistake is to hear ad libitum as "anything goes" — real freedom comes from preparation, not from skipping it.
Read deeper → rubato
Sources
- ad libitum 的用法与历史，参 The New Grove Dictionary of Music and Musicians, "Ad libitum"；本文为原创表述
Used for fact-checking only; all prose is original.