Beats Music CEO Ian C. Rogers:
Due to the extremely high volume of interest in our service some users are experiencing issues. Most people are unaffected but our priority is to give everyone a great experience. We prepared for issues like these, have a plan, and are going to hold off on letting more people in while we put this plan in action.
Those of you who got on board yesterday, please keep using Beats Music. New folks, download the app, register, and we’ll drop you a line as soon as possible inviting you back in. Everyone who registers this week will get an additional seven days added to their trial. link
It's funny that they were “prepared for issues like these”, and that those preparations apparently must have involved plans to cut service for new signups during launch week instead of having some additional server capacity at hand. Not exactly a testament to reliability.