ad libitum

In music, "ad libitum" (often shortened to "ad lib") is a direction that means a performer can omit a part or play it according to their wishes. It translates from Medieval Latin as "in accordance with one's wishes" or "without restraint or limit". This concept is closely related to improvisation, which is the extemporaneous composition or free performance of a musical passage. While improvisation often adheres to stylistic norms, it is not bound by a specific written text. Many great composers, particularly on keyboard instruments, were masters of improvisation, and this practice remains a key characteristic of genres like jazz.1234