A specialist music festival is best when it takes the broadest possible approach to its subject. So it was a thrill to see Robert Plant taking the blues back to Africa and then to outer space with an extraordinary backing band from Bristol, Liverpool and Gambia.

Limiting itself to one venue now, this year’s Bluesfest has packed an impressive number of must-see concerts into four days, though the two-sitting, curfew-straining system is not audience friendly. Plant had to prune his regular setlist to let folks out for the last Tube, a shame when nearly every song was a wild, wandering jam that turned even the most obvious Led Zeppelin classic into a new creature. Plant, his mane of hair still lustrous, stood surrounded by the backing group he called The Strange Sensation before he shifted into Americana with Alison Krauss and Band of Joy.

What made them the Sensational Space Shifters was new member Juldeh Camara, a Gambian master musician who plucked and bowed at his riti to coax irresistible grooves from an instrument with only one string.

Spoonful, a blues favourite made famous by Howlin’ Wolf and Cream, was unrecognisable by the time John Baggott had given it a looped electronic introduction and Camara and drummer David Smith had shifted that into a slinky African rhythm.

A heavier The Enchanter featured Plant and Camara bashing tambourines in unison, connected by the beat despite their strikingly different attire.

The psychedelic backdrop and joss sticks on the monitors evoked rock of a different era, but this late-night, loose-limbed melding of musical continents most recalled Damon Albarn’s more recent, epic Africa Express concerts. It contrasted starkly with so many of Plant’s peers, trapped by the need to photocopy their greatest hits. “This is an invigorating time,” he said — for us as well as him.