A particular emphasis on harmony is one of the core concepts underlying the theory and practice of Western music. The study of harmony involves the juxtaposition of individual pitches to create chords, and in turn the juxtaposition of chords to create larger chord progressions.

As a simple answer, harmony is when two sounds are played in unison. If you play the notes C – E – G melodically you get individual notes from the C major scale. If you play C – E – G harmonically, at the same time you get a C major chord. This is what is meant when we talk about harmony.

Music harmony is defined as being where 2 or more notes are played/sung simultaneously. The resulting relationship between these different notes is described as the harmony. This harmony can be heard between just 2 notes or extended further to 3 notes (a triad) or beyond to form complex extended chords.

Harmony is when multiple notes or voices play simultaneously to produce a new sound. The combined sounds in harmonies complement one another and sound pleasing. Chords and chord progressions are examples of harmony. A chord has three or more notes that play at the same time.

In its simplest form, harmony occurs whenever two or more pitches are played at the same time. It also refers to the 'backing' chords which often accompany the melody in songs. Much of ear training and music theory practice is devoted to a study of harmony.