Towards the end of his performance, Yusuf smiles and turns round to his right-hand man, guitarist Alun Davies, recalling an earlier visit to the Royal Albert Hall. "When was it – 1974? – with all the fog, when we last played here?" he asks, and learning it was '72, explains to us that on that night, the fog had been so thick he worried that nobody would be able to make it to the show. But when the Cat stepped out on stage, the place was packed. "That was a great night," he muses. "But this one might be better."
Tonight, it's not the fog but London's tortuous, knotted traffic that poses problems for punters, and I'm not the only one to miss the "bonus 25 minute showcase" of Yusuf's new musical Moonshadow. But by the time the man himself strolls out, strumming the intro to "Lilywhite", the place is once again packed with fans who, this time, have each paid up to £100 to see him play. The revenues, he tells us, will go towards setting up one of his MAQAM centres, designed to promote the recognition that ultimately, "we all believe the same things". And certainly, everyone in the Albert Hall could agree on one tenet at least, which is that Yusuf seems like a thoroughly nice bloke, the kind of Muslim you could take home to meet your mum and the Pope.
For a while, I wasn't so sure – there was a touch of smugness about his introduction to "Where Do the Children Play?", which he links to the Copenhagen Conference, hoping that the politicians "get the message – they should have by now, I sang about it 30 years ago." And the bit when Yusuf takes a break to have a cup of tea, sitting on a packing crate to tell a Tillerman tale, the moral of which seems to be that we should empty our minds of opinions in order that someone else can fill them up with other opinions, does rather resemble the teapot calling the kettle opinionated. But despite these misgivings, and despite his career-long leaning towards tweeness, it's ultimately impossible to dislike a performer as genial and engaging as Yusuf.
Most pop stars, particularly in this age of computer-slick stage presentation, would regard his frequent fumblings with his guitars – forgetting where the capo goes for a certain song, struggling to get back in tune, etc – as shamefully unprofessional, but for Yusuf they have become an endearing aspect of his character, an implicit acknowledgement of the many years his fingers spent estranged from strings and frets. But the minutes spent tuning are well worth the wait, as the rich, resonant interplay between the guitars of Yusuf, Alun Davies and Eric Appapoulay rolls back the years in songs such as "The Wind" and "Where Do the Children Play?".
Eight songs into the set, the backdrop rolls up to reveal a further trio of keyboard and percussion players, who bring an extra punch to the show, adding garage-rock organ on "I Think I See the Light" and harmonica parts played through a sampling keyboard on "Bad Brakes". But it's ultimately the songs themselves that are the key to Stevens/Cat/Yusuf's enduring appeal, songs which at their best – notably "Wild World" and "Peace Train" – ingeniously profess liberal political sentiments with such subtle power that they can get respectable, middle-aged matrons up on their feet, punching their fists in the air.
Tonight, these cornerstones of Yusuf's canon are prefaced respectively with a new Zulu verse and a brief blues variation, perhaps his way of coming to terms with the past on which he turned his back for so long; though that didn't seem a pressing concern when, buoyed by the acclaim for the climactic "Moonshadow", he responded to a fan's hopeful request by singing a joyous medley of "I Love My Dog", "Here Comes My Baby" and "The First Cut is the Deepest", songs which have probably lain dormant for upwards of three decades. Yusuf may well have pondered, as he sipped his post-gig cuppa, the lines he wrote back in 1972: "You're gonna wind up where you started from".