This might be common knowledge, but I don't know the answer... please don't rip me apart for not knowing!
What is it about Acrobat - why have they never played it live?
Personally, I don't find it difficult to sing. While I'm not a musician, the rest of the music seems very similar to "Until the End of the World."
Have they ever explained why they don't play it live? It's a great song, IMO.