Forty years after Simon and Garfunkel's Sounds of Silence, here we are listening to it all over again. Although, unfortunately, tonight's version isn't quite as good. Jason Mraz has been steadily building a following on the back of his album Waiting for My Rocket to Come, and despite the fact that Gary Jules was headlining in the wake of his unfeasibly successful Christmas chart-topper Mad World, it is Mraz who draws the loudest screams, and whose songs a hardcore coterie of fans know by heart.

But a tiny amount of Mraz can go a long way, despite the amazing multi-octave range and clean, flawless timbre of his voice. He stands at the microphone in a stripey bobble hat, rambling interminably about Valentine's day, his love life, and the traumas of the travelling troubadour. All of this might be excusable if his songs weren't equally shaggy and reluctant to get to the point. Mraz could probably improvise his way through Fowler's Modern English Usage without ever blundering across a memorable musical phrase. And while he can hop nimbly between fey balladry and too-bleeding-clever pseudo-jazz, just try finding a punchline or a chorus to hum.

Gary Jules has been hailed by VH1 as "the best American singer-songwriter to emerge out of the late 90s", which tells you a lot about VH1. In fact, he is a plodding journeyman who got lucky with a freak cover version of a peculiar song, and the more he bigs up his own material, the less convincing he becomes. He writes dated, derivative folk-pop songs that draw by rote from James Taylor, Don McLean and Cat Stevens. Only his duets with Mraz on Sir Elton's Rocket Man and an astounding version of Simon and Garfunkel's America lift proceedings beyond the mundane.

· Gary Jules plays the Cockpit, Leeds (0113 244 1573), tonight and the Hop & Grape, (0161 832 1111) Manchester, tomorrow.