A piano roll is a long roll of paper, approximately 11¼ inches wide, with thousands of small holes, or perforations, punched in rows over the length of the roll. The position of each perforation directly corresponds to a note on the piano. The rolls are made specifically for use in a "player piano", or as they are sometimes known, a "pianola". A player piano is a modified piano, and is generally larger in size to accommodate the additional mechanics required for the automatic player system. They were very popular in the early to mid 1900's but are rarely seen today. The words to the song are usually printed on the roll, and are visible as the music is played. The overall sound is much fuller than usual, as the roll can simultaneously play what at least three pianists could.