Relative Minor

Within the major modes, every mode built on a major 3rd has a relative minor — a mode built on a minor 3rd that uses the exact same notes. ionian (the major scale) pairs with aeolian (the minor scale), lydian with dorian, and mixolydian with phrygian.

The pairing comes from a shared major pentatonic: the relative minor keeps all of the major mode's notes but takes a different note as its root — the one a minor 3rd below the major root — so the same notes now sound minor.