Hi
Yes you can load them.
The name the B2 applies to the music is obtained from the names of the folders in which it is stored.
Artist / Album / music files belonging to that album
Arrange your mp3 music like this and you can upload it using the web interface (from a directory on your PC), or you can put it on a USB drive (that has been FAT32 formatted), plug this into the B2 and load it from that using functions available from the front pannel.
Finally you could turn on the B2's NAS and use that to copy the music onto the B2.
Fred