Have you checked out SoundBocks? https://soundboks.com. Source: about 1 year ago

I had a look at the SoundBoks this weekend at an event I was playing at. It had only a 10ms delay which was pretty awesome. This is out of your price range at 1000 USD, but mentioning here for anyone else looking for wireless portable speakers: Https://soundboks.com/. Source: about 1 year ago

Starting Monday, April 4 at 4PM CET/7AM PST—and repeating every Monday at the same time for the following weeks—we will make a limited number of batteries available for sale on soundboks.com through the regular product page. We’re limiting purchases to only ONE PER CUSTOMER. It will be first-come, first-served, and when the week’s supply is gone—it’s gone. But there will always be the next week :). Source: about 2 years ago

Nice idea. I have previously used https://jukebox.today will try this out. Source: over 1 year ago

If you want some music, you can put together a playlist that people can listen to in real time. I've never used this website, but https://jukebox.today/ is an example of something you can use to do this. Hope this helps! Source: almost 2 years ago

I found jukebox.com (I have never used it, but here is a brief description). Source: over 2 years ago