When John McLaughlin was a teenaged blues guitarist in Yorkshire in the 1950s, he printed business cards with the proudly declarative legend Johnny McLaughlin: Electric Guitarist. Five decades, scores of albums, and thousands of performances later, he is still happy to go by that moniker. ‘I grew up with r&b and rock ‘n’ roll, as well as jazz,’ he said recently in DownBeat. ‘It’s under my skin, the electric guitar.’

But even mild familiarity with McLaughlin’s recorded output reveals a fundamental ambiguity about the role of electricity in jazz – or at least in his own music. For every album full of guitar heroics...