I've finished the chapter and quiz on Mastering...super helpful chapter, and one I'm sure I'll be revisiting a lot in the future until I have it down myself! The video sessions showing other engineer's processes are really helpful.
At the studio, we had the guitarist from the previous two sessions, Rick, come back in for overdubs. Rick's a great player, and mentioned a lot of really talented artists for me to look into that I'd never heard of before. It's great to be involved with such talented, gracious musicians.