New World Symphony in the US wanted to develop new concert formats that attracted new, younger and less-experienced concert-goers. They developed four formats. To give them all a chance of success, all four were programmed each season for three years and carefully evaluated. The tested formats varied from 30-minutes mini-concerts to club night concerts ending with a full-on party. The general conclusion was that alternative concert formats do attract new audiences. This document sums up the results of the research.