this would be a cool feature alright. im wondering about how much complexity it would add to the codebase though

Very nice LDAP Server
https://github.com/glauth/glauth

LDAP authentication would be great. All of my other self hosted services use LDAP to have a single point of user administration. That's one of two reasons to use Subsonic.

Maybe some http header based auth with automatic user creation is easier to implement? Then everyone can choose the prefered auth system (ldap, openid connect, saml...). I use http header based auth with FreshRSS and it works really great. To connect the any apps, the user must login and create an "app password" of course.

looking at this again, I'm not sure its possible given the subsonic API's auth mechanism using query params. if anyone has any other ideas please reopen 👍

I'm not sure about how it was implemented, but Airsonic-Advanced has LDAP authentication.