Contour is the overall ‘shape’ of a song. While structure refers to the order and length of sections within the song, contour refers to how those sections relate, how they react to each other, and how they flow.
Contour includes the rises and falls in energy level, the establishment and return to main themes, and the development of musical elements. When a song has a well-defined and sensible contour, the listener will better understand the music and feel the anticipation and excitement as intended. When a song has a poor contour, the listener will feel lost and alienated.
A song with a good contour will have variations in energy level. Periods of high energy energise and excite the listener, whereas periods of low energy provide relief and anticipation for the listener. Effective placement of high energy sections and low energy sections is an important consideration when designing the structure of a song. If the changes are too slow, you lose momentum and the listener’s attention. The changes are too fast, you don’t give the listener enough to recognise and latch on to.
Musical themes give your listeners a way to remember parts of the song – not just after listening to the song, but during it. By establishing one or two main themes at the beginning of the song, you can then guide the listener through familiar material and unfamiliar material. A good song needs both, for similar reasons as needing different energy levels. Familiar material provides reassurance and recognition for the listener, whereas unfamiliar material provides excitement and development. Of course, too much of either will make for a weak song (too much familiarity becomes boring, too much unfamiliarity sounds like randomness). A good contour will require effective placement of familiar and unfamiliar material to guide the listener through the song.
Traditionally, musical themes are entirely melodic (or harmonic) – recognisable motifs, melodies, chord progressions, or other such material. Depending on your own approach to music, however, thematic material may also include characteristic sounds, or even distinctive effects processing.
A song with good contour will unfold and grow over time and take the listener along with it. Not only that, but the development of the song will occur in a deliberate way throughout the song – working together with the flow of energy and the placement of musical themes. I’ve written more about development here:
With a good understanding of contour, you’ll be able to make your music more engaging and enjoyable for your listeners. More than simply being a collection of musical ideas, good contour will give your song shape and cohesion.