The work presented in this thesis concerns unpredictability in popular music and provides an investigation into how unpredictability may be received and perceived. Most popular music is marked by an emphasis on predictability, with the aim of fulfilling the listener’s expectations. Pop songs are designed to be instantly memorable – a quality drawing upon simple melodies, much repetition and structural familiarity. Pieces of popular music that utilise unpredictability may be regarded as taking up a critical position towards the popular music industry’s dependence on, and reluctance to look beyond, songs that are familiar in both form and content.
During the 1960s and 1970s, a number of rock groups, inspired by the avant-garde, set out to prove that commercial forms of music could be vehicles for progressive and experimental ideas. These groups, in particular Frank Zappa’s, were successful at incorporating unpredictability into popular music. Zappa’s approach to composition exposed the formulaic characteristics of popular music, with the intention of discovering new and unconventional musical forms. His cryptic treatment of thematic materials draws comparisons to cryptography in the sense that meaning is often hidden. This thesis expands on this idea through an investigation of encryption algorithms and their musical application.
Set within a broad historical context, covering aspects of the avant-garde as well as popular music, different methods of achieving unpredictability are investigated, such as serialism, randomisation and improvisation. It has been found that there exists a dialectical relationship between order and randomness, to the extent that, under certain conditions, order may be perceived as randomness (described as “quasirandomness”) and randomness may be perceived as order (described as “quasiorder”). An investigation of how these two conditions may be used musically contributes an important line of enquiry throughout this thesis, with compositions and etudes serving to demonstrate the application of the new techniques developed.