Locrian Scale

The locrian scale is the mode built off the 7th note of the major scale. It differs from a major scale because it has a lowered 2nd, a lowered, 3rd, a lowered 5th, a lowered 6th, and a lowered 7th. The characteristic note is the flattened 5th but doesn't need to be avoided. This scale is pretty uncommon and the only place to use it would be a minor 7 b5 chord. However, a better choice is usually to play a major 9 on the chord instead of the flattened 9th or just leave out the 9 altogether.