Is it possible to earn money on a blog without ads? Or with ads, yet without turning the blog into one of those smeared in ads from top to bottom?
1) Ads.
2) Affiliate links. Affiliate links work well if your blog is an authority on products, especially for expensive products like musical instruments.
3) Promoting your own product, like an ebook, course, etc.
Which monetization method you use depends on how it fits into your blog’s content and audience.
Personally, I would do all three to maximize revenue.