Joining a room in Chrome Music Lab is a simple process that requires no registration or login. To join, navigate to the Room page on Chrome Music Lab's website and click on the “Create Your Room” button. From there, you will be given the option to enter your desired room name and password before clicking “Create”. Once created, share the unique URL of your room with others so they can join. When joining an existing room, simply enter the correct name and password to gain access!