The company Andreas Christensen started production of pianos in 1912 in Copenhagen, Denmark. They employed contemporary designers and architects to work on the ascetics of their pianos, including Poul Henningsen, Torben Christensen and A. Skjøt-Pedersen. Andreas Christensen had repeated collaboration with the architect and social critic Poul Henningsen, PH, leading to the production of a variety of pianos and pianette. The best known was his design for the innovative and modern piano PH grand piano in 1937 that bore his initials, in the same way as his PH lamp 1926 for lamp manufacturer Louis Poulsen. The PH grand piano is on display in several museums of art and design, including the Metropolitan Museum in New York and the Danish Design Museum in Copenhagen. It was also used by Alvar Aalto for the music room in his Villa Mairea.