Ad Lib(er Abaci)

Performed by Natalie Brooke Higgins (horn)

Instrumentation: Solo horn in F

Duration: ca. 4 minutes

Year composed: 2013

Place composed: Kansas City, Missouri

Dedication: Composed for Shannon McCranor

Program Notes: The title Ad Lib(er Abaci) is a play on two Latin phrases, each of which refer to aspect of the piece. The first, familiar to all musicians, is “ad libitum,” often shortened to “ad lib,” meaning “at the discretion of the performer.” This refers to the free timing of the piece: Each line of music is assigned a time limit, but within that limit the performer is given rhythmic and interpretive freedom. The second Latin phrase is “Liber Abaci,” meaning “The Book of Calculation,” the title of Leonardo Fibonacci’s seminal mathematical work in which he described the sequence of numbers that now bears his name. The piece is organized by means of the Fibonacci sequence. The first section lasts for 89 seconds and the second for 55; the first idea returns and is developed for 34 seconds, and the second for 21; and so on until each idea returns for 1 second and the piece ends. Ad Lib(er Abaci) was composed for Shannon McCranor, who premiered the piece in Kansas City, Missouri on February 3, 2014.