Harmony, Melody & Rhythm

Music is usually described as three things working together: harmony, melody and rhythm. Harmony and melody both describe relationships between pitches; rhythm describes relationships in time. Between them they cover what notes you play, how they relate, and when they happen.

Harmony - the vertical

Harmony is what happens when notes combine. Stack two or more notes, whether you sound them together or one after another, and you have harmony. It is the vertical relationship between pitches - a lattice or network of how notes sit against each other - and it lets you talk about how a whole piece's structure moves and changes. Intervals and chords are harmony.

Melody - the horizontal

Melody is also about pitch relationships, but read horizontally: it is how notes behave in sequence. The same handful of notes played in a different order make a different melody, even if, taken as a set, they share the same harmonic structure. A good melody plays with and against the underlying harmony, building tension as it moves away from the centre and releasing it as it returns.

Rhythm - the time

Rhythm is the relationship between sounds in time, regardless of pitch: how they pulse, how fast, how regularly. Music is a time-based art, so an understanding of duration and pulse matters just as much as which notes you choose - it is simply studied less often than harmony and melody.