When playing chord progressions there are notes that do not stand out as prominently to my ear. Usually these notes are the inner voices of the chord between the bass and treble notes, or maybe the weaker intervals of a chord. Instead of using higher voices to move melodies or the bass, what about the inner voices as a melody and the rest of the voices as sort of an accompaniment?

Is this common to do? The thing I find though when doing this is that it doesn't seem to sound so good because the other voices are always sticking out so much and sort of ruins the whole thing of inner voice melody.
Unless you re-enforce it somehow the highest note in a chord will generally be heard as the melody.
And no, Guitar Hero will not help. Even on expert. Really.