Melody is one of the most immediately apparent elements of music. It can be defined as a series of notes strung together, the musical equivalent of a sentence. When you listen to a piece of music, "the line that sounds most important is the melody," according to music teacher Catherine Schmidt-Jones, as cited on Connexions.org. A melody--like a sentence--may be composed of a number of musical phrases. The phrases within the melody may be separated by a pause. Melody as an element can also be described as a line. In most cases, the melodic line is easily distinguishable from harmonic elements.
"Music cannot happen without time," according to Schmidt-Jones. "The placement of the sounds in time is the rhythm of a piece of music." We come into contact with various rhythms every day. Speech has a rhythm to it. The sound of footfalls, of water dripping from a faucet, or rain against a window has its own rhythm, consistent or not. Young children learn to pound out rhythms on toy drums or makeshift instruments. And when you move or even clap to a piece of music, it is the rhythm to which you are responding. Rhythm can also be referred to as a "pattern that is repeated throughout the music...." This pattern may also be called a "rhythmic line." Rhythms are typically composed of a series of beats, some more pronounced than others.
"Harmony functions as accompaniment to melody," according to Cartage.org. Schmidt-Jones describes harmony as "more than one pitch sounding at the same time...." Harmony, sometimes referred to as "harmonic line" typically undergirds the melodic line. In Western music, harmony is often based on major or minor chords. Major chords offer a sweeter sound; minor chords contribute a darker feel to a piece. Sometimes the relationship between melody and harmony can seem "harsh" or leave you feeling uncomfortable. This effect is known as dissonance. In most pre-20th-century Western music, dissonance was frowned upon. Modern compositions, however, often include dissonant harmonies.