In regards to what version of
Surf's Up they're going to put in, I came across this article a couple days ago in which Billboard.com interviews Mark Linett.
http://www.billboard.com/#/features/beach-boys-engineer-talks-about-the-smile-1005071622.story...we can put Brian's vocal back into "Surf's Up," which was a group track in the 1970s [on the "Surf's Up" album]. Brian recorded a basic track with a full band for part one. And he also recorded a sort of a demo version, its just him double-tracked and a piano track. What the band did was they used the part one backing track and tried to fly Brian's vocal into that, but the technology at the time really made that impossible. So what happened was that Carl sang the [lead] vocal and overdubs were added [forthe Surf's Up album version]. And for the second half, they used Brian's piano vocal piece and added very few additions.
With the technology we have today, its much much easier to take Brian's vocal for part one and put it onto the backing track. I have done it and its quite nice. Now we have the ability to shift time things very easily so those synchronizations can be accomplished.