Yes. During the trial period, you are restricted to 100MB of total uploads. Once you upgrade to on of the paying subscriptions, that 100MB limit is lifted. Files can be linked to songs, services, and teams you have created. Much like a file server on your office network, WP does pays no regard to the type of file that is upload unless our virus scanner detects it to be a threat.
To learn more, including who can access uploaded files and how what WP lets you do with MP3s, read the Upload Files article.