Across the top of the screen, you'll see a handful of tabs. Click the Music tab to control what music you synced to your Shuffle.
- Sync Music - Check this to add music from iTunes to your Shuffle.
- Entire Music Library Syncs all your iTunes music to your Shuffle (big surprise, right?). Since most people's iTunes libraries are larger than their Shuffles, you probably want be able to choose this option. Instead, you'll want to select the next option.
- Selected playlists, artists, and genres
- Choose this to control what music is synced from iTunes to your Shuffle. Sync playlists by checking the playlists you want on the left or everything from a given artist by checking the boxes on the right. Sync everything you have in a a particular genre, or just a specific album, by clicking the bottom boxes.
- Automatically fill free space with songs - Fills unused space on your Shuffle with music that's not already synced to it (obviously this doesn't work if your Shuffle is already full).