Using functions to express musical ideas is nothing new: Harmony, time signatures, the relations between notes in a scale and musical form all have their roots in mathematics, and composers have used mathematical abstractions for millennia (see Pythagorean Tuning for a 2500-year-old example). These abstractions, however, are not always obvious from they way that music is written down, leading to a potential disconnect between composer and performer. In this post, we will use Steve Reich’s 1972 Clapping Music to show how functional programming can be used to capture an underlying musical idea.
I recently attended one of the coding dojos run by the London Scala User Group. It was great fun, and I’d recommend getting involved to anyone who’s interested in meeting other developers and learning more about scala and functional programming. After breaking into groups, we set about tackling the ‘LCD Digits’ problem from cyber-dojo.org. Although fairly straightforward as a programming challenge, it offers a number of ways to experiment with different functional idioms. The goal is to write a program that takes an integer, and formats this as a string composed of the ‘.’, ‘_’, “|’ and ” ” characters so that the output resembles an LCD display.