Usually basics are as follows: Brooks, Baker and Jay play the songs, and Graffin usually sings and "talks" the song. What they're really trying to focus on is a stellar take from Brooks. Jay tries to lay down something easy and basic so the guitars and vocals have room to play later. Baker's are just scratch takes to support Brooks. After all the drums are done, Baker will do most of the guitar work with Brett, then Graffin will sing the main and doubles. Then Baker will do some solo work, then background vocals, then Jay will lay down the very last tracks on bass.^[1]

Jay: "We will usually a/b a few snare drums and bass guitars, amps, etc... just to get a feel for what we are going to work with (same with guitars and amps, and vocal mics). That usually involves Joe Barresi (or whomever is in the studio) and Brett.
Usually in pre-production we will try a song faster and slower than its original tempo just to see how it feels. There is usually a groove that a song fits into.
What you really want to find in the studio are the "magic moments" that no one could write, just drum fills or bass riffs, guitar leads and vocal inflections that weren't originally planned. Those spontaneous moments are sometimes the best part of a song. I know there are basslines that I can never play again. I can get close, but I don't even really know what I did."^[2]

References