Learning music by ear is done by repeatedly listening to other musicians, either their live shows or sound recordings of their songs, and then attempting to recreate what one hears. This is how people learn music in any musical tradition in which there is no complete musical notation. Audiation involves hearing sounds mentally, although on a different level than just "hearing a song in one's head". In addition to mentally hearing rhythms and pitches the skill of reproducing those sounds involves melody, harmony (chords) and bass line. In the West, learning by ear is associated with folk music, blues, rock, and jazz. But many classical music forms throughout the world lack notation, and have therefore been passed from generation to generation by ear.