Update, TCG found this excellent live version:
This was one of the albums I had as a kid. Almost too sweet for my normal taste, but too good.
I love what they did with the female vocal in the last third.
I think, as an artist, it's a little bit of a pity: the album cover and the title suggest something epic, something timeless. (Avalon is the island from the King Arthur legends.) And the music really lives up to that, grand, bigger than life. But then when you listen to the lyrics, they're about a party and dancing.