In 1820, Hall left Riley’s shop to establish his own firm. In 1821 Firth and Hall entered into partnership to form the firm of “Firth & Hall”. The pair enjoyed great success in the music industry.
In 1833 Sylvanus Pond was admitted to the partnership, forming the firm of “Firth, Pond & Hall”. Firth, Pond & Hall lasted until 1847, and was a major force in New York City’s musical trade during that era. William Hall withdrew from the firm in 1847, and his previous partners formed the firm of “Firth, Pond & Company”.
Hall then entered into partnership with his son, James F. Hall, to establish “Hall & Son”. Hall & Son continued to be a successful maker and retailer of musical instruments, including piano-fortes, melodeons, woodwinds, etc. Their pianos were known to be of superb quality, and the won many awards at fairs and exhibitions during the middle 19th Century. In 1870 James Hall withdrew from the firm to join the military, and William G. Hall continued to head the business of Hall & Son until his death in 1874.
During these last years, pianos by the firm were labeled as both “Hall & Son” and “Wm. Hall & Company”. Pianos built under the Hall & Son (sometimes listed as Hall & Sons) were built until the World War 1 era, but it is unclear which family members were in control of the company by the early 20th Century. It is assumed that the firm continued to be controlled by decedents of William G. Hall.