I recently came across this brief description of modes:
"The word ‘mode’ comes from the Latin for ‘manner, or method’ but musical modesall originated in ancient Greece, so they have Greek names. The modes were namedafter various regions, perhaps to represent the people who lived there, becauseGreek musical theorists were philosophers too, and associated the arts withaspects of morality.Bascially a mode is a type of scale, as in ‘doh re mi fa so la ti do.’ Alterjust one of those notes and you can call your scale a “mode”. Long before peoplestarted thinking about pieces of music having “keys”, each mode is believed tohave begun on a different note of the scale, conferring its own character to theset of notes running, for example, C to C (Lydian mode) or E to E (Dorian mode)and so on.The seven main categories of mode have been part of musical notation since themiddle ages. So, the list goes: Ionian, Dorian, Phrygian, Lydian, Mixolydian,Aeolian and Locrian. Some of them are major modes, some are minor, and some areambiguous. Some modes are sadder or holier than others."