Thanks for the reply. Your code works fine with the free demo MP3 file you checked. But it doesn't work with MP3s that can only be accessed with an emusic.com account. But thanks to your code, I now know the reason:

http://content.emusic.com/downloads/472279/Sean_Deason-Allegory_Metaphor-01-Creation.mp3

gives me the following LWP error message:

LWP::Protocol::http::request: HTTP/1.1 403 Forbidden
LWP::UserAgent::request: Simple response: Forbidden

So I guess my question is: how to get the size of a restricted file, where an HTTP request for a header does not work? Am I still in the right place to ask this question?