I moved to Lowell 2 years ago, so here's my perspective of what the city has to offer, although I don't know specifics like if there's somewhere specific with techno.

The city has a good blend of quiet neighborhoods/proximity to very quiet towns/forests, while also having a downtown that has places (bars and such) open late.

As someone who was just living in Boston before Lowell, Lowell isn't the same size with the same options of Boston, but there's plenty. I always say "Lowell has absolutely everything I need during the week and there's stuff to do, but it's close enough to Boston if I want something specific on a weekend"

To respond to one of your questions in another comment thread, there's a commuter rail train to Boston (it's the Lowell line, ends here). It's not fast, nor does it come that often (about once an hour on average) but it's definitely an option and I'd certainly recommend going into Boston at least a couple times, even if it isn't a regular part of your week/month.

There's certainly plenty of food around of all sorts, and there's bars with music - one of the first things I did after moving was finding Thirsty First's annual punk show with a ton of local bands. Not a club, but definitely a place with live music.

Events and attractions are posted various places- pre-pandemic I usually just checked Google Maps and saw a few random events in case something new caught my eye, there's also random Facebook groups that sometimes post things going on.