Mel, Like you and Don, I too am mostly a 'find the style and play it' guy for the majority of my audiences which are NH/AL venues ... I still do some multi tracking, sometimes adding 'back up singers' to the tune ...
But case in point about 'style and play', working an Assisted Living gig yesterday I was doing 'Down By the Riverside' to a strong shuffle beat and the crowd was singing all the 'Down By the Riverside' parts ... I just segued into "Goody Goody', "Just a Gigolo", and a number of others and closed the show with about 20 minutes of songs to that style with the crowd singing all the tunes ... They loved and the AD it and so did I ...