There are seven scales in classical music that go back hundreds of years, they are in accending order the Ionian, the Dorian, the Phrygian, the Lydian, the Mixolydian, the Aeolian and The Locrian. They begin let's say on the white keys of a piano or a guitar with the major scale or Ionian which goes CDEFGABC.
The next classical scale is the Dorian which starts at D and goes DEFGABCD. No sharps or flats. The Phyrgian scale is EFGABCDE, the Lydian scale is FGABCDEF, the Mixmolydian scale is GABCDEFG, a major with a flat seventh, the Aolian scale is ABCDEFGA or the A minor scale, and the Locrian scale is BCDEFGAB. These are all the seven classical scales.
What makes it a particular classical scale is the note you start on which is the bass note, for example the left hand of the piano or the bass guitar would be playing that note for you to play over. There is a simple way on the guitar of playing all of these classical scales with only one shape, the minor shape, or whichever one you choose to transpose. Lets say you like the minor scale shape and your bass note is always A. Starting with A minor scale, move the shape of the notes you are playing up two frets, until you are playing the B minor scale.
With the A bass note the B minor scale is the A mixmolydian. ABC#DEF#GA. Now move up to the C#minor scale and you are now playing A Lydian scale. ABC#EbEF#G#A. Move up to D minor over A and its the Phrygian scale, E minor over A and its the Dorian scale, F# minor over A and its the Ionian scale (or major), and G minor over A and its the Locrian scale. There are only seven classical scales, but they can be played in many different ways.
Using this method, you can play all the classical scales by remembering one shape and its relative starting point to the bass note. As you can see the order of which minor scales fit is determined by using the mixmolydian scale as a guide for which minor scales to play over the bass note.
To see a full list of my free video guitar lessons, check out my Facebook page: Guitar lessons online, and you can contact me at rowancasey@bigpond.com if you live in Hobart for a guitar lesson from my home. If you want to get paid to write articles, join Bukisa.