When she returned, she introduced her "Attar of Roses" sermon, based on the Song of Solomon. In October 1931 McPherson held a revival in Boston, a city with large Unitarian, Episcopalian, and Catholic populations, traditionally hostile to Pentecostal messages. On opening night, McPherson spoke to fewer than 5,000 in the 22,000-seat sports arena. The following day, her campaign's tone shifted and attendance climbed sharply. The final day of afternoon and evening services saw 40,000 people attending, exceeding the stadium venue's capacity and breaking attendance records.