Ages ago I read it, about an old lady who gives piano lessons to men. She gets them to play mindlessly simplistic single-note runs, over and over and over. When the student comes back to inform her that the piano exercises are driving his wife crazy, the teacher responds along the lines of “good - exactly”. One scene breifly describes a bunch of scruffy biker types hanging out in her kitchen, and I believe by the end of the story the teacher is found dead by railroad tracks.
title/author?
I have no idea, but I do have a public service announcement. Do NOT Google “piano teacher short story”. Especially if anyone else has access to your Google history…
You can’t just let that hang out there.
Probably because this is one of the first links? (Sorry, OP, probably not the one you are looking for.)
Exactly. Half of the first page of results are smut.
Gadzooks, google results turning up smut?! Has someone informed the media?
Seems to be annoyingly paywalled.
Thanks anyway for everyone’s input.
Is it The Last Question by Asimov? 
No. Clearly it’s Alan Dean Foster’s novelization of “Rio” by Duran Duran.
Smut, you say? Feast onthis.
Or indeed this
I look forward to Chuck Timgle’s Pounded in the Butt by Not Being Able to Access the Story You Want to Read Behind a Paywall.
Thank you.