The relative minor is the 6th of the respective major; for example, A is the 6th of C and so A Minor is the relative minor of C Major. Such a pair shares all the same notes (exact same black and white piano keys) but start at differing points.
This is often depicted with the circle of fifths.
Basic examples:
| Major Key | Relative Minor |
|---|---|
| C Major | A Minor |
| D Major | B Minor |
| E Major | C# Minor |
| F Major | D Minor |
| G Major | E Minor |
| A Major | F# Minor |
| B Major | G# Minor |