Undelete deleted Linux files with lsof

Briefly, a file as it appears somewhere on a Linux filesystem is actually just a link to an inode, which contains all of the file's properties, such as permissions and ownership, as well as the addresses of the data blocks where the file's content is stored on disk. When you rm a file, you're removing the link that points to its inode, but not the inode itself; other processes (such as your audio player) might still have it open. It's only after they're through and all links are removed that an inode and the data blocks it pointed to are made available for writing.