The dense A-band is further traversed by a lighter H-band.

H-band is the zone of the thick filaments that is not superimposed by the thin filaments.

Gregory, who has been regularly involved in Steve Hogarth's h-Band, has also contributed to works by Porcupine Tree, including string arrangements on their sixth album, Lightbulb Sun, and for Dublin group Pugwash.

An array of thin I-band actin filaments (each some 5nm in diameter) extends from the Z-disk to the edge of the H-band in a relaxed fibre, while thicker myosin filaments (each about 15nm in diameter) run throughout the A-band.