Celtic Woman – an Amazing Musical Group Performs Amazing Grace Celtic Woman is a group of Irish singers and a mini orchestra that accompanies them. The group also features an Irish fiddler, who for several years was Máiréad Nesbitt. Máiréad. A new fiddler has arrived to continue this tradition. The quality of the group of singers, musicians and staging and costuming is truly world class – with a distinctive bit of Irish brogue.