 The overwhelming popularity of his instruments was due to inexpensive construction and price.Over time, square pianos were built in larger sizes with more keys and a wider range; by the 1830s, square grand pianos predominated, with changes to their internal mechanisms and construction that produced larger sounds and used higher string tensions.Square pianos were the most popular keyboard instrument of the late 18th century, and the later square grand pianos enjoyed great popularity through the mid- and late-19th century.