 However, the change in focus from a community orchestra to a full-time professional orchestra led to financial difficulties, and concert attendance began to recede.Canadian Brass, which in 1979 was the first brass ensemble to play the main stage of Carnegie Hall, developed much of its repertoire and style while performing in front of thousands of Hamilton area school children as part of the Hamilton Plan.In 1984 Michael Quigley published a book about the orchestra, "A Centenary History of the Hamilton Philharmonic Orchestra".