https://fretwork.org/ https://fretwork.org/fretboard-notes https://fretwork.org/intervals https://fretwork.org/octaves https://fretwork.org/triads https://fretwork.org/major-minor-chords https://fretwork.org/pentatonic-scales https://fretwork.org/major-minor-scales https://fretwork.org/harmonizing-the-scale https://fretwork.org/note-association https://fretwork.org/circle-of-fifths