Watching DVDs on the Mac in OS 9.2.1

[Carol]

I know this shouldn't be difficult.  I know I have done it before.

I am using OS 9.2.1 on a G4 Sawtooth with the original CD/DVD drive.  I
thought that booting up using the Mac OS 9.2.1 All or Basic set of
extensions would work.  It doesn't.  Those extensions don't even let me
play an audio CD.  

Does anyone know what I need to play commercial audio CDs and DVDs?  It
must be in the extensions somewhere.  These must be on, these must be
off.  That sort of thing.

--
Carol -