Par CHAPMAN CHARLES. Drop-2 chord forms have been used by guitarists in all musical genres for years. The concept refers to 4-way, closed voicings in root position or any inversion, dropping the second note from the top by 1 octave, hence the term 'drop-2'. In practice, a nifty guitar harmonic symmetry occurs as drop-2 chords are invariably played on any four successive strings, muting or avoiding…