Abstract
'Easter eggs' are hidden components that can be found in computer software and various other media including music. In this paper the concept is explained, and various examples are discussed from a variety of mediums including analogue and digital audio formats. Through this discussion, the purpose of including easter eggs in musical mediums is considered. We propose that easter eggs can serve to provide comic amusement within a work, but can also serve to support the artistic message of the artwork. Concealing easter eggs in music is partly dependent on the properties of the chosen medium; vinyl records may use techniques such as double grooves, while digital formats such as CD may feature hidden tracks that follow long periods of empty space. Approaches such as these and others are discussed. Lastly, we discuss some software components we have developed ourselves in Max/MSP, which facilitate the production of easter eggs by performing certain sequences of notes, or as a result of time-based events. We therefore argue that computer music performances present unique opportunities for the incorporation of easter eggs. These may occur to the surprise of audiences, performers and composers, and may support the artistic purpose of compositions as a whole.