Several iTunes Store accounts, one computer

In my family we have one shared Mac connected to the stero as our "music machine". Can I give myself and the children their own iTunes accounts so that we all can buy music using our own accounts, but still have everyone's purchased music playable on the same shared computer? (And preferrably using the same shared user account on this computer?)

I guess that the question could be re-phrased as is it possible to authorize the same computer to more than one iTunes Store account without setting up individual user accounts on the computer?

thx