The improbably gangly Gil Scott Heron saunters onto the Savoy stage like a goodwill ambassador from another, less frenetic era. Clutching a conciliatory white towel, his greying hair bursting out in clumps from beneath his baseball cap, he looks for all the world like a kindly grandfather figure come to entertain at a children’s party.

It’s an image he does little to dispel with his chucklesome introduction to ‘Showbusiness’; when he fluffs the piano line barely a minute into the song, he insists that he wasn’t even playing the instrument, merely

miming for his brother the ventriloquist.

Scott Heron, however, is the man who first announced that the revolution would not be televised, and it isn’t long before he launches into a spirited diatribe against CNN, “the only station with experts on shit that never happened before”. He also speaks of the recent “sort of election” in his native America, “which the man with the least votes won”, a development which causes him to wonder if anyone has ever actually attended an Electoral College.

Scott Heron is soon joined on stage by “the brothers” – a drummer, percussionist, bassist and saxophonist – and things get very lively indeed. This is protest music without guitars, and the band are no spring chickens, but their playing is superlative, and the crowd sway and bop as the rhythm demands; the sax on songs like ‘Working In A Graveyard’ is almost transcendental.

It’s no surprise that a well-seasoned song like ‘War Going On’ still packs a punch, particularly when delivered by visitors from that great nation which, in the absence of any more fearsome enemy, seems intent on waging war on itself. “Peace isn’t the absence of war”, intones Scott Heron, “it’s the absence of the rumour of war, the preparation for war, even the talk of war”. One wonders if America is listening.

The call for decommissioning doesn’t quite end there, of course. ‘Work For Peace’ continues the theme, and leads into the seminal ‘Winter In America’. Then Scott Heron rises from his keyboards and dances the ‘The Monmonko’, urging the audience to celebrate as he and the brothers take their leave, returning, after a prolonged ovation for a rapturous encore of ‘Hold Onto Your Dreams’.

Come the revolution, CNN will know which expert to approach for his opinion on the matter.