Here's an example of a song that made the jump from the writing room to the studio:
"Breakthrough" (Ben Cooper/Jenn Schott) ©2010
Exhibit A - Writing room version, immediately after finishing the song (Jenn singing):
Exhibit B - The full-band demo recording (artist Mallory Hope singing):
In the course of three hours (the length of each "session"), a band of musicians will usually record five songs. Broken down, that's a song every 40-45 minutes, at a quality that sounds like something you could hear on the radio. The way this proficiency is accomplished is by having the songs mapped out ahead of time by the session's lead musician (here is an example of a chart written using the Nashville Number System).
When the time comes to begin recording the next song on a session, the players all congregate in the mixing room to hear the songwriters' rough recording (Exhibit A). They follow along on the charted road map, jotting notes along the way. After hearing the song only one time, the players take their places in the soundproofed tracking room and run through the tune. Then after a little banter about who should take the solo and when and where each player should come in, they play through the song for the final pass (Exhibit B). Generally the final demo version of a song is literally only the second time these players have ever attempted the song! After the band's tracking session, a demo singer or artist will come in and overdub the final vocal, and the engineer will mix the songs, sometimes even the same day.
These session players and singers are some of the most talented individuals I have ever been around. I wish I could bring everyone into the studio on days that we are recording, because it is such an amazing process to see. I believe that the most "Nashville" thing that a tourist could ever experience is not walking down Broadway through honky-tonk bars, but rather sitting in a studio while a song comes to life before their ears. And this is an experience that I hope you are all able to have someday soon.