There's a similar anecdote in Iain M. Banks' The Player of Games.

https://scifi.stackexchange.com/questions/270578/negotiator-...

Thanks for pointing it out.

I'm putting together a database along the lines of https://www.whosampled.com/ except instead of samples in music it's fiction authors either:

- revisiting one another's ideas

- stumbling across the same idea independently of one other

Now I get to add an edge between Tchaikovsky and Banks. It's somewhat unsurprising. Tchaikovsky does this a lot.