Sharing old music from iTunes to Facebook messenger issue

I have old recordings of me performing in the 70s at my college that I want to share with friends using Facebook messenger. But unlike purchased songs, where there is the three dots that give me an option to share the music, I look in that same area, but there is no option to share these songs. I guess because they are so old? But they are still in my library nonetheless. How can I share these music files from my iTunes library to Facebook messenger? Is there a workaround?