Tool’s guitarist Adam Jones is a long-time fan of drop D tuning. This allows him to get weight into his phrases while establishing a tight, identifiable tonality that sits alongside the bass. Additionally this tuning, which ‘drops’ the sixth string down a whole tone to D, enables him to alternate between single-finger powerchords (root-5th-root), single-note riffs, and melody lines.
Tool’s music often explores a range of emotions, so it’s not uncommon for the rhythm guitar to shift between heavy, mid-tempo powerchord sequences, and sustained arpeggiated figures that form subdued, melodic motifs.
