From my own experience, Harvey is one of the most approachable people on the folk scene, he is normally more than happy for people to sing his songs, as he says himself " a song not sung is a dead song". However Silas if you like one of his songs on a CD you may well find several others that you want to cover so the purchse of a CD could well be a superb investment in new material for you

Cheers

Raggy