A lot. They are based on form, symmetry and division. For example, there are only four positions on the guitar before you have duplication of notes. And there are only four registers, too.
The diminished chord shows you that in a capsule: You have four diminished chords going up the fingerboard before you hit the fifth, which is a duplication. That’s because the diminished chord is the division of one octave into four equal parts.
The guitar is totally based on chromaticism. A lot of players see the guitar as an arrangement of frets. I, instead, see it as a reality where the fingerboard can be broken down into five chromatic scales and a duplication. Therefore, it reduces the terms of redundancy.