Bach's friend Telemann is also relatively unknown today. He was extremely productive and there are lots of great pieces, I especially love some of his trumpet works. They are played on the radio occasionally.
Thanks for bringing up Telemann. I wouldn't say he's unknown today, but definitely not in the "pop" composer category the way Bach is. His music is definitely in the repertoire of most serious violinists while studying late Baroque.
Here's one I studied for a while when I was studying the instrument many years ago.
I was always torn between playing Baroque music in the modern style or in the contemporary style. I find incredible enjoyment in hearing the music on period instruments played in the style. The music's texture changes so much.
