There's also the BBC's Virtual Session complete with sheet music.

As near as I can tell Scoiltrad is no longer?

This looks like a useful one: MAd for Trad.

With a three year old grandson, I really like the sounds of their CD tutorials for kids:

Irish Music CD ROMs for Primary Schools         

        MadForTrad.com are pleased to offer an exciting set of CD ROMs for primary school children, which supports the Primary Music Curriculum (1999). High quality video clips show performances and interviews from some of Irish Music's finest exponents.

The text focuses on the Listening and responding strand and is divided into levels from infants to 6th class. It can be used individually by the child, or by the teacher as the basis for a whole-class activity. An extension of their use is in the home by parents and families.