Music Revision
Relative Keys:
In music, relative keys are the major and minor scales that have the same key signatures. A major and minor scale sharing the same key signature are said to be in a relative relationship. The relative minor of a particular major key, or the relative major of a minor key, is the key which has the same key signature but a different tonic; this is as opposed to parallel minor or major, which shares the same tonic. Relative keys are closely related keys, the keys between which most modulations occur, in that they differ by no more than one accidental (none in the case of relative keys)
The minor key starts three semitones below its relative major; for example, A minor is three semitones below its relative, C Major.
G major and E minor both have a single sharp in their key signature at F♯; therefore, E minor is the relative minor of G major, and conversely G major is the relative major of E minor. The tonic of the relative minor is the sixth scale degree of the major scale, while the tonic of the relative major is the third degree of the minor scale.

> (marked near note head) | Accent: emphasis on a particular note | A triad is a chord of three notes. | |

The chord built on the first note of the scale, I, is called the tonic. The chord built on the fourth IV is called the subdominant and the V is called the dominant. These chords are also known as the first, fourth and fifth degrees of the scale. * A concord is a chord where all the notes seem to 'agree' with each other, it feels at rest and complete in itself. * A discord is a chord where some notes seem to 'disagree' or clash giving an unsettled feel. * Diatonic harmony uses notes which belong to the key. * Chromatic harmony uses notes from outside the key to give the chords more 'colour'.

Cadences
A cadence is formed by two chords at the end of a