How can I improve my universe that I’ve created?

I’ve created a universe where when musicians died on earth, they go to Equestria.

How can I improve on that?

7901002
So, I haven't read your works, but based on this description, the next step I would take is to shift the focus away from musicians you want to see in Equestria, and maybe add in some bad musicians.

That is to say, those people that stand outside of Target and pretend to play an instrument for donations, but when you lift to bow from their violin, their music doesn't stop because they weren't really playing.

Or the people who say they only sound bad because their instrument is cheap. No joke, I found out that a lot of people think cheap electric guitars are made out of plywood because it's cheaper (they usually aren't). Meanwhile, there are actual guitarists that just play a shovel because the skill is in their fingers. A good instrument does make a difference, but four hours of practice every day on my beat-up, chipped, dented, paint-peeling hunk of junk electric guitar that I paid a whole five bucks for sounds better than the discordant, out-of-time, out-of-tune "Mary Had a Little Man" played on a top-of-the-line model any day of the week.

So that's my suggestion on where to build next; turn your concept on its head.

7901043
I should just you read my works.

But thank you for your input. It really helps.