Also learned that David's recording was done in the last 2 weeks before his mission. He recorded with basic arrangements and did 4-5 takes of each song. After he left the full arrangements and the duet were added. And Kurt Bestor says all background vocals are David.
And BTW if anyone is on Twitter he is DavidArchie - he can't tweet or read twitter from his mission so his manager Kari is doing the updates and sometimes she includes a bit from one of David's mission emails (he can email her every week or two)