At the start of the 18th century, there were two similar instruments which were played using a standard keyboard, the harpsichord and the clavichord. Both had weaknesses: the volume of these instruments was not dynamic nor particularly loud. In 1709, Bartolomeo Cristofori produced what he called a “gravicembalo col piano e forte,” which translates roughly to “harpsichord with soft and hard.” But it wasn’t until the introduction of iron in piano construction that the modern piano began to take shape. In 1856, Steinway & Sons of New York made one of the biggest advances in the history of piano building, which included the manufacturing of the first “grand piano” with a one-piece iron frame. At about the same time, the keyboard had grown from a modest four octaves to today’s standard seven and a quarter octaves or 88 keys. Today, the piano exists in several configurations, the most universally revered being the nine-foot grand piano, though “baby” grands and upright pianos make up a significant percentage of piano purchases because of their relatively small size. Electric pianos, such as those manufactured by Wurlitzer and Rhodes, gradually earned their own place in the evolutionary process by virtue of their mobility and characteristic sound, both of which earned them a place in modern jazz and rock combos. By the beginning of the 20th century, the modern grand piano was perfected and since then, has remained virtually unchanged.