I recently learned that there's a harmonic reason why some scales exist. If you have a minor scale but want to have a dominant V chord, sharpen the 7th degree and as a byproduct you get the harmonic minor scale. If you have a major scale but want to sustain a VII chord, flatten the 7th degree to have a major VII(b) chord; as a byproduct you get the mixolydian mode. Is it useful to think of the lydian mode as a major scale altered in order to have a major II chord in the common II - V - I?
(Regardless of the answer, can someone point me to a tune that uses a II - V - I with a major II chord?)