I couldn’t access the YouTube link you put in, (I’m short of some or other thing) and I am frightfully curious – I did not know that the Glissando Waltz is a beginners piece on piano too. How is the glissando represented on piano?
Yes, they do slide across the keys. Lots of instruments other than the harp play glissandos, after all. We just have lots more of them and they sound so much better. 🙂
As for youtube, you don’t need to create an account at all, unless you want to upload videos or post comments. When you go to that link, isn’t there a play arrow at the left of the timeline? What operating system are you running?