By Denny Dyroff, Entertainment Editor, The Times Colin James, Matt Andersen & Terra Lightfoot There are several upcoming shows at area venues that feature three or more interrelated acts. One features bunch of local musicians and the other showcases a trio of top-flight Canadian acts. On May 5, the Sellersville Theater (24 West Temple Avenue, Sellersville, 215-257-5808, www.st94.com) will...