Whatever would Robert Johnson, self-styled King of the Delta Blues, have made of the Black Lives Matter movement? His was certainly a life that mattered, but it was lived at a time when black lives mattered not a jot to white America. The circumstances of his death in 1938, at the age of 27 (he was probably poisoned by a jealous rival), demonstrate the disenfranchised existence of any peripatetic black performer in Depression-era USA.