By Denny Dyroff, Entertainment Editor, The Times Stephen Kellogg Stephen Kellogg has always maintained a dual career – as a solo artist and as a leader of his own band. He spent the first decade of the 2000s recording and touring with his band The Sixers. On June 4, Kellogg is returning to a venue that was the site of one of his first post-Sixers era shows — the Bryn Mawr Twilight Concert (9...