Freeze the opening of Jimi Hendrix's Purple Haze and, amid the heavy octaves and feedback, you can isolate an iconic sound, a chord consisting of E, G#, D and G natural - a chord at odds with conventional laws of harmony - a chord that underpins the whole of the blues, rock and jazz.

The 'Jimi chord'- contains Rock's DNA ... With music by Jimi Hendrix, Led Zeppelin, Bobbie Gentry and Dungen and contributions from Steve Howe (Yes), Reine Fiske (Dungen), Steph Paynes (Lez Zeppelin), Bernie Marsden (ex-Whitesnake), Asa (Rainbow Bridge), Franklin Dawson (Shiva) and John Campbell (Are You Experienced), Alan Hall devises a musical analysis of the harmonic posture of rock.

Press

"a cunning way of discussing the fundamental mysteries of music, how a cluster of noises somehow generates feeling and meaning."
Robert Hanks, The Independent, 21 November 2007