Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Yamaha DGX-620 is the European name of the digital piano known in the US as the YPG-625. It was released by Yamaha Corporation in late 2006, the first model of the DGX/YPG series with weighted keys. The DGX-620 is an improved version of the earlier Yamaha DGX-520 keyboard. In June 2008 the Yamaha DGX-630 replaced the DGX-620 (aka YPG-635 in the US). A digital piano is a modern electronic musical instrument designed to serve primarily as an alternative to a traditional piano, both in the way it feels to play and in the sound produced. Some digital pianos are also designed to look like an acoustic piano.