When we listen to a melody, we’re usually able to understand if it sounds good or bad after just a few notes are played. The underlying cognitive processing employed to arrive at such an assessment – although extremely sophisticated – is carried out on an almost unconscious level. It all feels so natural that we don’t realise how many simultaneous elements are contributing to the overall experience. Indeed, a melody is a complex musical construct that involves many musical domains at once. There is pitch content involved, obviously. But a melody also comprises note durations, rhythmic and metrical elements, accents, structural relationships between the different subsets of the melody, articulations and dynamics.
We may not be aware of it, but most music that we’re used to listen to is linear. Linear music has a beginning, a development and an ending that sound exactly the same every time we listen to it. The soundtrack of a movie, the songs of Bob Dylan and a Mozart’s symphony are all examples of linear music. Linear music works great if it’s used for concert music or as musical background for fixed media. Every time we watch Star Wars, for instance, the sequence of events occurring on screen are always the same. No matter how much we would like it to be different, (40-year-old spoiler alert) Obi-Wan Kenobi is going to be killed by Darth Vader! The fixed structure of a movie is great for the composer who has to write the soundtrack, because he or she can create musical cues that are specifically tailored to the on-screen images on a moment-by-moment basis. When the cannons of the Millennium Falcon hit the ships of the Empire, for example, the explosions can be underlined by the music and the overall excitement of the moment can be captured and enhanced by the soundtrack.