The Locrian scale is the seventh mode of the major scale. Locrian is a difficult scale to listen to as almost every interval is altered. The formula for the scale is 1 b2 b3 4 b5 b6 b7, so it is quite difficult to make pleasant music with this scale on a static vamp. However, in context over an m7b5 chord in jazz and fusion style chord progressions, it has its place. This scale can also be used over altered dominants as an alternative to the more commonly used Super Locrian, which is mode seven of melodic minor. The only way to get fluent with any scale is to practice it on its own, before tackling chord changes, so although this scale is difficult to listen to, it is vital that you practice with it so you can use it.