By DENNY DYROFF, Staff Writer, The Times   Davina Sowers is a performer who provides a conduit to the past for many people — of all ages. She and her band the Vagabonds make music that hearkens back to a different era in America’s history of popular music. Sowers sings as if she were fronting the … Continue reading On Stage: Davina & The Vagabonds, Jonny Wickersham & AMT’s ‘Deck the Halls’