If you merely wish to retrive bpm information for songs, you do not need to register. Registration ensures that no one floods the system with bogus information as a user is only permitted one bpm entry per song. If the same user tries to upload bpm information for a song that they have already submitted information for, it will update the current information instead of adding a new record.
Also, as a fail-safe against bogus information being submitted, all submissions for a song are averaged; the more correct entries for a song that are submitted, the less a rogue entry will matter.
E-mail addresses are only used to ensure that no user enters information for the same song more than once and is not sold or used to send spam. In fact, the only time you will ever be e-mailed by Music Reviews is if you request that your password be resent to you.
Developers, please download the source code examples for submitting and retrieving bpm information. This code is licensed under a 3-clause BSD style license and can be used in commercial projects. I encourage anyone working on iTunes, Banshee, Amarok, last.fm, Rhythmbox, etc. to add the ability to connect to this database so that everyone may benefit.
If you would like users of your plugin to skip the account registration process, you can register a generic account that your plug-in will use. Keep in mind however that all of your users will overwrite eachothers submissions.
Please note, Hotmail users may not receive the confirmation e-mail. This issue is being looked into.