Plan B, 02 Arena, London

Four years ago, Plan B aka Ben Drew was a mouthy hoodie-clad rapper from east London whose acclaimed debut album offered such odes to the street as the inspired "Mama (Loves a Crackhead)".

Now, he's a firm PG-rated family favourite, shown by the hordes of screaming teenage girls, parents with children in tow, and coach-loads of over-fifties who erupt into adoring applause when a thoroughly respectable 27-year-old Drew strides out on to the stage sporting a crisp black three-piece suit.

It's the last night of Drew's UK tour to promote his incomparably different second album, the concept record The Defamation of Strickland Banks, which reached No 1 in the UK charts. And Drew's transformation into the fictional character of Banks is nothing short of gobsmacking.

He kicks off with the summery Motown of "Writing's on the Wall" from said second album, followed by an impressive rendition of "Welcome to Hell". His vocals offer beautifully executed retro soul, with blues and swing influences, and it's clear that Drew's talent is underlined by homework – even his chat is tinged with a Rat Pack accent.

There's nothing new about a "gangster" being remodelled as a smooth crooner but there are hits and there are misses. Just look at Frank Sinatra at the top end of the spectrum, verses Brian Harvey from East 17 at, well, enough said. Numbers such as "Praying" showcase Drew's flair for fulfilling the top end of this brief, but his soulful sentiments on the huge hit "She Said" are undermined by absurd riot-police dancers faux-fighting with a "street" crew. It smacks of bad Nineties pop showing that for Banks, there's a thin line between the sublime and the ridiculous.

It's only the encore that shows how powerful he set can be. Finishing off with a return to his rap roots with of "No More Eatin'", Plan B is spitting passion, and shows he's got a whole lot more than soul.