sentences:  As many as 15,000 people attended these admission-free events, at which all display counters and fixtures were removed by an army of workers so that seating could be put in place.Under Wanamaker's guidance famous organists were brought to play the Wanamaker Organs in Philadelphia and New York, including Marcel Dupré, Louis Vierne, Marco Enrico Bossi and Nadia Boulanger.Wanamaker also sponsored a Concert Bureau to book European organists on trans-American concert tours.