In 1993, Sheryl Crow professed that all she wanted to do was have some fun. Fifteen years on, however, things have got a lot more serious.

A fight with breast cancer and a broken engagement with cycling champ Lance Armstrong have caused Crow personal strife, while the US's foreign policy has been the target of a number of public outbursts from the enduring troubadour.

Last night it initially appeared that Crow was in no mood for a love-in. Without a word or a smile, she began the sombre set opener God Bless This Mess, a refrain on the troubled situation in Iraq from her forthcoming album Detours.

While it was an intimate and brave way to start things, the muted reaction it received suggested it was not exactly what the many middle-aged couples in the audience had in mind on Valentine's Day.

The breezy reggae of Love Is Free was closer to the mark, with its bright acoustic guitar and gentle percussion drawing parallels to fellow eco-friendly peacenik Jack Johnson.

Predictably, the biggest cheers were saved for the old classics. Strong Enough prompted a mass singalong, while Everyday Is A Winding Road eventually got the crowd moving with its infectious beat and bottleneck guitar riff.

Crow will play Hyde Park in June, in a bill that includes Eric Clapton. If she keeps the music for the stage and confines the politics to Speakers' Corner then it will be one not to miss.