Yankee, I don't agree at all. It's VERY memorable.
During and immediately after I saw the show, I HATED it. Then the next day, I couldn't stop thinking about it. The day after that, I couldn't stop thinking about it again. Songs that weren't stuck in my head were now in my head. I HAD to buy the CD. Things made sense...later.
Whether a show is supposed to have an impact on you during or after is my question. SPRING AWAKENING changed the way I see what theatre can be. I hated it, but now love it.
PS: Performances don't HAVE to be memorable. That's just a bonus. The STORY is what has to be memorable. While Christine Ebersole gave a memorable performance in GREY GARDENS, the show isn't all that memorable. In SPRING AWAKENING, the show is memorable, but not so much individual performances (more really the entire ensemble).
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle