Modes
Same seven notes, seven different homes.
Seven homes, one set of notes
Start the major scale on a different note and you get a different mode — a different mood, with the same raw material.
The lineup
Ionian bright, major Dorian minor but hopeful Phrygian dark, Spanish Lydian bright and floating Mixolydian bluesy major Aeolian natural minor Locrian the odd one out
Why it matters
Modes are how the same seven notes become funk, metal, flamenco, or folk. The difference is which note you call home.