Common, Shepherds Bush Empire, London ***

Maybe what they say about DJs with exceptionally loud systems is true – they do have a tendency to blow out the speaker stacks. The ear-splitting assault of the hip-hop favourites played before Common and his six-piece band take the stage seems to have left significant damage. When the band rock harder and Common's delivery becomes more urgent and emphatic the distortion becomes harsher, the exuberant free-flowing assaults cruelly branded with a cauterising sizzle.

This is a shame, because the man born Lonnie Lynn Jnr is a beacon of ambition and audacious technique. His latest album, Electric Circus, is a kaleidoscope of influences covering the waterfront from Miles to Hendrix, from psychedelic rock to old-skool hip hop. His songs' concerns go beyond the hip-hop norm, covering issues such as a friend who comes out as a gay man, an aunt who refuses chemotherapy, anti-materialist rants and a lover who confesses to the pain of child abuse. We aren't on Planet Bling Bling any more, folks.

Despite the sound problems, the new album is a great springboard for a live show where Common presents himself as a soulful evangelist and hip-hop ringmaster. His determination to explore parts of the mind and body that most big-league rappers are too cool or blasé to care about is obvious from the moment he launches into the energising quasi-manifesto of "New Wave".

Prowling the stage in his trademark Beanie hat, Rockers T-shirt and tracksuit bottoms, Common's insistence that the crowd raise their arms to fan the frenetic grooves or punch the air in defiance does not solely play to the audience participation norm: few performers are as concerned with communicating the enormity of their musical vision as Common. The band mix sideshow calliope loops, reggae offbeats, turntable scratch mixes, muscle-knotting funk, Quiet Storm soul and much else besides.

In word and deed, Common takes time to praise a long list of influences, including his one-time adversary Ice Cube, and gives many examples to bear out his belief that hip hop is the most inclusive and forward-thinking means to musical liberation.

On a raging "Electric Wire Hustle Flower", his frustration with the malfunctioning speaker seems to boil over and he begins to mercilessly trash the equipment with his mic stand. The sound doesn't improve, but the spectacle makes for great theatre, as does his impressive display of head-spinning break dancing.

When he sets an audience member – Estelle from Hackney, east London – on a stool to philosophise on the meaning of commitment, he manages to avoid loverman cheesiness and booty bravado in a performance that is both moving and unnerving.

What lets him down is pacing and knowing where to stop; the show's impact was lessened by too many workouts that are designed to show the band's finesse rather than Common's exalted vision. But misplaced generosity and sound problems aside, in the field of present day hip hop, Common is something extraordinary.