How do I get musty smell out of basement?

Basements can get so musty smelling. Here’s how we solved the problem: https://www.frugalfamilytimes.com/2019/04/how-to-get-rid-of-musty-smell.html

To prevent musty smell due to humidity, I use electric devices that absorbe water from the air.

Once the smell is around, I'd burn lavender flowers.

We have two dehumidifiers running at all times. That's the only thing that helps us.

For musty odors, you could also get a little bottle of NilOdor. That stuff works great, just put a few drops around the room.

I found another idea for you too

https://www.familyhandyman.com/article/how-to-get-rid-of-that-musty-smell-in-your-basement/

Be sure to have a dehumidifier - that will make a huge difference! No moisture means less mold growing in places you can't see it which causes the musty smell. Then lots of Christmas tree scented candles. :)

If you do not have a dehumidifier then you should purchase one. You can set it up so that it runs into a floor drain and you will not have to worry about emptying it. During dry, warm weather, open windows so that the air movement will help to dry it out. You could also install a ceiling fan and just let it go so that the air circulates. On rainy days, keep windows closed and let the dehumidifier do its job.

Dehumidifier to remove moisture. Buckets of damp rid will accelerate the process. Clean with odoban for a nice fresh scent to remove odors.