Most probably use a music service of some sort. I don’t DJ anymore, but these are a few of my old favorites:

• Promo Only: https://promoonly.com — This one has been around forever. Pricey but recommended.
• MP3PoolOnline: https://mp3poolonline.com
• Direct Music Service: https://www.directmusicservice.com

I’m sure there are a whole lot more too!

This is perhaps for a narrower audience, but if you run a consumer version of Windows (not Server), you can get Backblaze unlimited storage for $70/year per device.

They support encryption with a key you provide in the client, which is super convenient. Restoring individual files is pretty straightforward, but an entire drive was a bit of work last time I had to do it. For the price, it’s a nice piece peace of mind for 10TB+ of versioned storage.