Here's hoping the mighty Gregory Porter doesn't become too smooth by half - review 

Ivan Hewett is as impressed as ever by the mellow richness of Porter's voice, but hopes he manages to keep a little grit in the oyster

No mere jazz singer, Gregory Porter is now a mainstream star vocalist. His trademark look of fur hat worn in all weathers and elegant three-piece suits have made him a marketable brand, as instantly recognisable as that amazing treacle-soft vocal timbre. It’s the combination of that massively authoritative voice and the touchingly confessional nature of his songs that has proved irresistible .

At this gig, made up of some songs from two earlier albums and a sprinkling of others from the latest one, we often heard that tone of disarming honesty. In Don’t be a Fool, where the band disappeared leaving only pianist Albert Chop Crawford to accompany, the tune and words were both guilelessly simple. Porter actually rhymed “in my arms” with “your charms”, an idea that could have come straight from a 19th-century salon song. It was saved from mawkishness only by the innate gravity of that voice.

But maybe Porter relies on that insurance policy a bit too much. Sincerity needs leavening with a little wit if it’s not to sound plodding. The new song Free aspired to being a funky anthem in praise of human emancipation, but the line about needing to try hard at school felt a bit leaden. These lapses were surprising, because Porter has a real verbal gift, which sometimes is tinged with high-flown almost Biblical rhetoric (as in the wonderful new song Take me to the Alley) or with a nice dash of humour, as in Be Good.