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.
Over time, grand pianos grew larger in size, with more keys and a wider range; by the 1830s, square grand pianos were dominant, with modifications to their internal mechanisms and construction that resulted in louder sounds and higher string tensions.