William Harrow & Son described themselves in 1865 as smiths, brass workers, gasfitters, inventors of the globular glasses for fishtail burners, music smiths, locksmiths and bellhangers.
In 1852 Harnden & Son, brass smiths were located at Harrow's address of 14 Portland Street, London. It is probable Harrow took over the premises from Harnden. They seemed to pare down their range as the company grew and later described themselves as music smiths and brass workers. Still later, this changed to music smiths and stand makers. The premises also expanded to encompass 13 Portland Street. By 1899 Charles Hare, Music Stand Makers had taken over 13 Portland Street.
Harrow were known for their American Portable Music Stand, later described as their New Patent Portable Music Stand and were active in the second half of the 19th Century.