[cjhanks]

There are different stages of composition in music. By the time you're playing music, you ideally should not think this way.

But it's nice to have a visual way of seeing substitutions that work with your progression as you write music.

Having an enumeration of all of the possible voicings is really nice.

When I looked at this (as a bass player), I didn't even really notice the fret board. This application is applicable to all instruments.