Modes
Seven scales share one set of notes; each starts on a different degree, so each puts the half steps somewhere new. Every row below plays its scale over the same tonic drone, so the only thing that changes is the color. Ordered brightest to darkest: each step down flattens exactly one more note.
The seven modes, one tonic
Pick the tonic. The drone holds it while the scale walks, so your ear measures every note against home.
Tonic
The two ends of the spectrum
Lydian raises one note above major; Locrian flattens five below it. Back to back on the same drone, the whole range is audible: