It took me a couple of days, about 6 days to be exact, to work my way up from level 36 to level 40. Now I can do the Record a Demo mission. Looking forward to trying that one out.
Also, with my Ego much lowered from before, the rewards per mission have more than doubled what they were. They were around 500 Starbits when I had 67+ ego. Now with 21% ego, the maximum rewards are up to 1275!
So what's next? The next obvious targets are level 45 for the Acoustic Tent mission and level 55 for the Local Mini-Tour Support mission. Getting there's going to take a while!
I'm going to do at least 10 Record A Demo missions with music lessons spaced in between. Hopefully I reach level 45 in two weeks or so. That's the target. Probably will buy a couple of packs along the way as well.