How can I force Rhythmbox to rescan the ID3 tags?

Here’s the situation: I start up Rhythmbox and I see hundreds of recordings of the song Unknown by the artist Unknown, taken from the albumn Unknown and typically of an Unknown genre 😉

So … I fire up EasyTag and I fix them, and now I have hundreds of identified tracks, but Rhythmbox still remembers them from the old tags, and that’s the information RB uploads to LastFM.

Is there some way to tell Rhythmbox to recheck all the ID3 tags? The only method I’ve found is to touch all the files and then stop and restart Rhythmbox.