There has been much research into the musical acoustics of the piano, including models of piano strings [554,23,78,79,142,42] and the piano hammer [501,64,179,60,497,164]. Additionally, there has been considerable work to date on the problem of piano synthesis by digital waveguide methods [471,524,527,56,42]. In this chapter (adapted from [471]), we will consider commuted waveguide synthesis of the piano. This method is capable of high quality piano synthesis at extremely low cost relative to other model-based approaches.