A few years back I made a hobby project like this -- it scraped the website of the local free weekly paper (since they have pretty much every concert listing, large and small) and then did a youtube search on band names so you'd see an embedded video or two for each show.

I think most larger cities (and smaller cities if they have a large university) have such a newspaper (e.g. Village Voice in NYC, Willamette Week in PDX, The Mercury in Seattle, etc)

Maybe it's better in the states, but where I live the papers don't come close to being a complete listing. They will have the major stuff, and some of the smaller shows too - but a large part is still missing. And it's not a small city - 2 mln people, capital, and quite an active music and culture scene.

Indeed, this sadly will not be scalable to certain cities where the data source is incomplete. The author had posted this on the Austin subreddit a few weeks ago and I asked him if the source of the data was Showlist Austin (http://showlistaustin.com/) and he/she confirmed that it was in fact at least one of the sources for the Austin data. It's great that we have that site for Austin but it's probably the only place I've ever been that has that complete of a list of good local shows.

Yes, the first website I ever made was in this space for Philadelphia. I wanted to make show listings with playable songs for every night of the week. I just manually found listings and found youtube links and built it. Every site I found always had a bunch of cruft. This was in 2011, figured it had improved by now. :)

How about crowdsourcing the info somehow, maybe letting people enter it for their city from some source and making that public for everyone?

I started such a crowdsourcing effort some time ago :)

https://www.reddit.com/r/MusicEventsHackers/comments/87ui5l/...

that is an intense google sheet. :)

Thanks, yeah I posted it to different music subreddits, so I thought I should try and make it eye-catching :)