Google is adding to its roster of Chrome Experiments today with the launch of a new JAM with Chrome web app, built using HTML5, CSS3, and the Go programming language. This new game gives you a broad selection of instruments to choose from and allows up to four friends to play together simultaneously. The latter aspect is rather reminiscent of other shared music creation games like Multiplayer Piano, but here you get to control who you jam with by inviting your friends along. Unfortunately, the invitation function wasn't working for us at the time of writing, but that shouldn't stop you from perfecting a fine guitar solo using your trusty old keyboard.