The "Wow!" and "Soundtrack!" sequences that were originally created for the THX WOW! laserdisc also appear on the "THX Ultimate Demo Disc" DVD.

I don't have the laserdisc. If it is a "squeeze" (anamorphic) disc, I'm sure it would be mentioned on LDDb - I'd be very surprised if the LD isn't standard 4:3.

I will have to check the DVD again, but although the Wow! sequence is anamorphic, it looked to me like an upscale. The Soundtrack! featurette is non-anamorphic; this is because it comprises a mixture of 4:3 fullscreen and 2.35:1 scope material.