So, I was watching the making of MTM a couple days ago when I noticed something. There is a part where it show the guys who conducts the strings and a guy playing a chello. There were recording at the time of filming. I just noticed it.
Yeah, I remember hearing it on the DVD. You can hear Across the Line too, that one's a bit more obvious.
When they're talking about hearing how the vocals sound before they write the lyrics. When they're just going "na na na na na na na".