Yes, when you've connected a device to your computer and selected it on the left-hand side of your computer's iTunes you can use the tabs on the right-hand side to select which of your iTunes content to sync to it - which may be the same, partly the same, or completely different selections to your iPhone. iTunes will remember your sync selections for each device - I sync an iPad, iPhone and iPod to the same iTunes and have different selections for each.
You can manually manage syncing and chose not to sync any music if your don't want any on it. Syncing music : http://support.apple.com/kb/HT1351