Another (semi)related goal is acquiring a collection of humanist and rational music that is as evocative as "religious" music, optimized for communal singing. I think Humanism and science have been kind of dragging their feet when it comes to producing inspirational artwork (or at least, they've been dragging their feet when it comes to publicizing it).

That's an interesting project. I can see two difficulties which might explain why there isn't a lot of such music. One is that lyrics at a high level of abstraction tend to not work very well, and the other is that many of the emotions associated with rationality aren't easy defaults for expressing through music.

This doesn't mean it's impossible, just that there might be some new territory to explore.