Pleyel pioneered the player piano with the Pleyela line of pianos. These were often very small pianos of a very unusual design.
Around 1815, Pleyel was the first to introduce the short, vertically strung cottage upright piano, or "pianino" to France, adapting the design made popular in Britain by Robert Wornum. Their pianos were such a success that in 1834 the company employed 250 workers and produced 1000 pianos annually.
The company's success led them to invest in experiments, resulting in the Double Piano in 1890, invented by Hungarian composer Emanuel Moor. Although not the first company to experiment with building two pianos into the same frame, Pleyel's instrument, patented as the "Duo-Clave", was by far the most successful and produced the largest instruments. The company manufactured a very small number of Double Pianos in the 1890s and continued to make them until the 1920s. CDs can be bought today of performances on some of these pianos.
In 1913, Pleyel built the "Jungle Piano" for use by Albert Schweitzer in his hospital in Lambaréné (French Equatorial Africa – now Gabon). It was fitted with pedal attachments (to operate like an organ pedal-keyboard) and built with tropical woods that would acclimate to conditions there.
Toward the end of the 19th century, the Pleyel firm produced the first chromatic harp. In the early 20th century, at the behest of Wanda Landowska, it helped to revive the harpsichord.