It's amusing to read the talk page on this article - there was lengthy investigation about whether this really had any Feynman connection (i.e. was the story about him apocryphal) and what the article should be called. I think the current title is fantastic - I would have struggled to name such a thing.
A sequence of many 9's in a row in the decimal expansion, which Feynman jokingly extended ... and 'showed' therefore pi was rational.
> I've got Pi/Listen going in the background, and it's quite pleasant
That is probably due to the choice of musical scale more than due to Pi. I believe the output of randint(0,10) on the same musical scale would sound just as pleasant.