1845, Oliver Ditson employed John C. Haynes, then a lad of fifteen, as boy of all-work at $1.50 per week. The boy so proved his worth that on his twenty-first birthday, September 9, 1850, he became a participant in the profits of the store, and on January 1, 1857, he was made a business partner and the firm name became Oliver Ditson & Co.

August, 1857, The Oliver Ditson Company moved to a building owned by Mr. Ditson at 277 Washington street. Around 1868 the street was renumbered and became 451 Washington street

1864, two young men, P.J. Healy and George W. Lyon, were established in Chicago by the capital of Oliver Ditson & Co., under the now honored name of Lyon & Healy

March 4, 1867, the firm purchased the music plant and stock and good will of Firth, Son & Co., of New York City. After remaining a few months at 563 Broadway where Firth, Son & Co. had been located, more spacious quarters were taken at 711 Broadway. The purchase by the parent house of the music catalog and business of Wm. Hall & Son, New York, in 1875, and of J.P. Peters, of New York in 1877, necessitated the taking of more spacious quarters in 1878, at 843 Broadway.