One man alone with his voice (no band, no instruments) in a large classical venue is not an entirely promising prospect. Bobby McFerrin’s performance at the Royal Festival Hall, however, was one of those rare experiences whose memory is likely to be savoured long afterward by its audience.

Bobby was dressed down: workboots, jeans, black ‘t’, but his music wore many costumes and hinted at an infinite variety more. He began by harping and humming and percussing into his microphone, drawing out a stepped circular piece that came on like that Escher print of impossible steps that just keep climbing every way you look at them. As he sang he took tiny, pigeon steps around the stage and used his breath in gasps and wheezes and pants and huffs and gulps and… you get the picture. Breath is central to McFerrin’s universe – as it is to most of us - but it’s not something practiced unconsciously, perfunctorily or snatched in the cracks between the notes, it is the percussive centre of McFerrin’s music.

At times his voice was a moth batting against a screen door, at times a car accelerating away into the darkness. He performed acts of magical transmogrification, melding an auctioneer or horse-racing commentator into the whispering of a spiritual so that it was possible to wonder whether visiting a bookmakers might be a religious experience. Don’t be misled though, every moment was tremendously musical, saturated with rhythm and melody.

Partway into the concert he was joined by a small amateur choir with whom he wove music like an African rug, the warp and weft of which was marked out with a rich, vibrant pointillism. In doing so he appeared to quietly reclaim the roots of Reich’s and Glass’s minimalism. Motifs were brought forth by the wave of a hand or the stamp of a foot loud enough to jolt both the audience and the choir in surprise. He went on to traverse musics ranging from Ave Maria to blues duets with a dancer and a trumpeter to duets with the audience and finally to a five minute compressed version of The Wizard Of Oz for an encore. This was a concert packed with event and interaction.

Listening to Bobby McFerrin was like listening to the jostling procession of humanity in all its colours and guises singing, talking, shouting, mumbling, keening, whispering. From moment to moment it seemed possible to hear hints of any number of languages, yet the very outlines of words shape-shifted at will: almost apprehended, then gone like faces in crowds.

This was not one man alone in a vast hall, but a medium both uniting with his enrapt audience and invoking and shaping the spirits of absent multitudes into a unique, inclusive music which ultimately spoke of hope for these troubled days.