I would recommend you to try SoLoud Library, I opened another thread a few months ago around audio libraries to use in Monogame and so far SoLoud seems to be working fine for me, but not sure about the scale of your projects. Check this thread
Also about OpenGL implementation, I am quite noob in that area since I was working on DX before, since I moved my projects now to multi platforms I started using OpenGL, any advice on why OpenGL is so bad in MG? or what is not working?