Brainwave Entrainment - anyone used it? (Plus some to try out...)

I know that some people aren't that keen on the idea of Brainwave Entrainment audio - but on the whole I have had some great experiences with it.  With that in mind I set up a section on my site, containing free brainwave entrainment audio.  At the moment there are alpha, delta and theta versions ranging from 40 to 60mins in length.

The theta is particularly interesting for deep meditation, visions and even lucid dreaming.  I understand that Bach music can produce similar theta effects - I would be interested in adding Bach to the site if I can find a public domain copy of the a performance - anyone know where I could find this?

Anyway the Online Brainwave Entrainment is available at my site for anyone that wants to give it a try...let me know what you think of it!