I use https://www.newshosting.com/ as my Usenet provider. I have the $14.95 plan for unlimited downloads. They include a reader program, but I prefer to use NewsRover. I'm not sure the company still exists, but here's a site that I think you can download a copy from: https://news-rover-usenet-newsreader1.software.informer.com/ I'm not sure how much NewsRover costs now. I think I paid around $40 for it. You might even be able to download it free now.

The basic process is to subscribe to Newshosting and get their news server name and other data. Then download NewsRover and use the info from Newshosting to set up your connection. Then you will download the list of newsgroups. That will take a while, as there are many thousands. Then you go through the list of newsgroups and subscribe to the ones you're interested in. You can type in search terms to narrow the list, such as mp3. After subscribing to one or more groups, you will need to tell the program a save location for each group. Also, you can filter the messages, for instance to only show those messages containing files to download. Then download message headers for a newsgroup, highlight the messages with files that you desire, and then download.

There is a learning curve, but I've been doing this for many years and have downloaded over a million mp3 files, plus photos, books, magazines, comic books, movies, and tv shows. The newsgroups also have software for download and discussions on any subject you can imagine.