Van Morrison / Solomon Burke, Royal Albert Hall, London

The potential that the double bill offered for a soulman super summit was certainly enticing – Solomon Burke, the veteran preacherman from Philadelphia, and George Ivan, the Belfast cowboy and mystic exile. But, the evening proved only to be a study in sharp contrasts: Burke's corny showmanship versus Van's near-paranoid reserve, the preacher embracing the crowd as a communal mass, the exile wrapped up in his intensely personal odyssey.

Sat on his stage-centre throne, mountainous physique clad in a spangly suit and cape, Burke's sonorous voice is a miraculous relic from the days when the soul clan ruled the earth. He doles out an endless supply of red roses to the faithful and offers mini sermons on love, war and peace amid a honey-flow of Sixties classics.

After he sings the Morrison composed "Fast Train", from his Don't Give Up On Me comeback album, Burke invites the crowd onstage during the Otis Redding tribute "Fa Fa Fa Fa Fa Sad Song" and calls for Van to join him. But, the party atmosphere hardly seems appropriate to the unpredictable Morrison temperament and the pairing never happens.

When Burke leaves and Morrison arrives, he's accompanied by a supper club-style combo with whom he coasts through worn standards and some perplexing, largely inconsequential selections from his recent albums. A small clenched figure in dark glasses, he seems the archetypal lost loner of the blues lore he was raised on. The voice is in fine shape, but he struggles to find settings that will enable it to fly. There are flashes where he raises the stakes – the wracked agony and searing harp in "Early In The Morning", and the emphatic "That's Life" provides a glimpse of the Sinatra covers album Morrison really should get round to recording.

But the call and response with trumpeter Haji Akbar on the trifling "Mama Don't Allow No Saxophone" is no match for the Pee Wee Ellis duels of the recent past. Too many blithely toe-tapping arrangements suggests that the directionless drift of his career has brought him to a tired impasse.

But there is a pay off. Introduced as "the workshop section of the show", his improvised version of "It's All in the Game" is a truly epic exposition of a melody composed by former American vice-president Charles Dawes in 1912. The tense body language disappears as he loses himself. His knees are bent, and he drives the band up several gears with long wordless moans and finally reaches the epiphany, discovering "the rainbow in my soul".

An electrifying departure from what had gone before and a reminder that – even in the midst of slumber – the wee man is a musical giant capable of unleashing awesome power.