Music is made up of sounds pitched at relative intervals. The spacing of these intervals makes a scale. There are several principal modes each of which can be found by starting on the notes A-G and playing up the white notes (only) on a piano to the corresponding note an octave higher. They are Aeolian (A-A), Locrian (B-B, rare), Ionian (C-C), Dorian (D-D), Phrygian (E-E), Lydian (F-F), and Mixolydian (G-G). These can be transposed to start on different pitches as the interval pattern between notes is the essential feature.
The modern major and minor scales correspond to the Ionian and Aeolian modes, respectively, and form the basis of most western music: (F=full-step, H=half-step, T=three half-steps)
