Hey there! This is a great site, and I'm sure it must hurt to let go of the project. The fact that you're looking to sell the project "fast" suggests to me that you might be in a bit of a tough spot. The fact that you care about being fair tells me you care about this project.
I've got a couple of suggestions.
1. If you are in a tight spot financially and need to sell the site due to some emergency, come clean about that to your users. Let them know that the site they love is in trouble. It may help give you a little infusion of cash that will allow you to keep the project going for a bit longer.
2. If selling is still in your playbook, you need to demonstrate your property's value. Right now your list is untapped and therefore I couldn't tell just how many of your users are buyers. You need to do that work for your buyer.
I see you have a Patreon, and that's a great start, but it's not necessarily compelling enough on its own. If I were you, I'd start with affiliate marketing.
Think about what your audience has in common. If they are classical music listeners, the odds are high that they either play an instrument themselves or want to learn how to play one.
For those who want to be a musician, the answer is obvious: become an affiliate for high quality music instruction courses online.
For those who already are musicians, you might have a better sense of their problems than I would. Maybe they're more interested in better equipment or instruments. Perhaps they are more focused on monetizing their music, in which case it would be a good idea to take a look at courses online that focus on the business side of music-making.
If you created the site I'm seeing online, perhaps another thing you could do is connect music instructors with music students by giving instructors the chance to sell their lessons on your platform in return for a percentage.
Another source of potential revenue could come from in the form of grants. Find a local university (perhaps your alma mater?) and see what the music department says. Other than teach and research, professors pretty write grants for a living. They may have some ideas for you.
If you are yourself a musician (and especially a music teacher) you may be able to create your own course and sell it online to your listeners. You could create a "beginner's guide to Classical Music" and teach people about it.
Classical Music also shares quite a lot in common with film scores; you could monetize by allowing your users to sell their music to film makers who need music.
I've got a couple of suggestions.
1. If you are in a tight spot financially and need to sell the site due to some emergency, come clean about that to your users. Let them know that the site they love is in trouble. It may help give you a little infusion of cash that will allow you to keep the project going for a bit longer.
2. If selling is still in your playbook, you need to demonstrate your property's value. Right now your list is untapped and therefore I couldn't tell just how many of your users are buyers. You need to do that work for your buyer.
I see you have a Patreon, and that's a great start, but it's not necessarily compelling enough on its own. If I were you, I'd start with affiliate marketing.
Think about what your audience has in common. If they are classical music listeners, the odds are high that they either play an instrument themselves or want to learn how to play one.
For those who want to be a musician, the answer is obvious: become an affiliate for high quality music instruction courses online.
For those who already are musicians, you might have a better sense of their problems than I would. Maybe they're more interested in better equipment or instruments. Perhaps they are more focused on monetizing their music, in which case it would be a good idea to take a look at courses online that focus on the business side of music-making.
If you created the site I'm seeing online, perhaps another thing you could do is connect music instructors with music students by giving instructors the chance to sell their lessons on your platform in return for a percentage.
Another source of potential revenue could come from in the form of grants. Find a local university (perhaps your alma mater?) and see what the music department says. Other than teach and research, professors pretty write grants for a living. They may have some ideas for you.
If you are yourself a musician (and especially a music teacher) you may be able to create your own course and sell it online to your listeners. You could create a "beginner's guide to Classical Music" and teach people about it.
Classical Music also shares quite a lot in common with film scores; you could monetize by allowing your users to sell their music to film makers who need music.
I hope some of these suggestions help. Good luck!