Norris, I have seen my share of bicycles from this era and it is most common to have single racing bikes with more pronounced drop handlebars and few with brakes. The large chainring and toe clips seem to say to me that this may have been an early racer converted for street use. As for the tandem, during that period it was very common to use tandems, triples, quads and yes I have even seen a 5 seater used for pacing racers before motorcycles were used.
Ray Homiski
Elizabeth, NJ