Bach's work is in the public domain, which means anyone can make their own recording. But, any recording of Bach's works will still automatically have its own copyright, unless it's intentionally dedicated to the public domain too. The great thing about a public domain recording is that anyone can take it and use in any sort of artistic or even non-artistic endeavour, without having to worry about the usual "Contact the copyright owner, hope they will grant you a license that's not too expensive."