The Boehm system is a system of keywork for the flute, created by inventor and flautist Theobald Boehm between 1831 and 1847. Prior to the development of the Boehm system, flutes were most commonly made of wood, with an inverse conical bore, eight keys, and tone holes (the openings where the fingers are placed to produce specific notes) that were small in size, and thus easily covered by the fingertips. Boehm's work was inspired by an 1831 concert in London given by soloist Charles Nicholson who, with his father in the 1820s, had introduced a flute constructed with larger tone holes than were used in previous designs. This large-holed instrument could produce greater volume of sound than other flutes, and Boehm set out to produce his own large-holed design.