You have perhaps noticed that Rytmee is out of order on Internet Explorer browser.
It is temporary and own to beta (test) version.
When the BETA version will be finished, Rytmee will be compatible on all browser: Chrome, FireFox, Safari, Opera, and Internet Explorer.
In all cases, the team recommend you to use Google Chrome. This modern broswer is faster and nicer to use for your personal broswing and for Rytmee.code of point @en