BWV 533, 549 and 578 are the basic level non chorale based organ works of Bach that serve as preparations for larger preludes, toccatas and fugues.
Here's what one of my student's wrote about BWV 549 Video Training:
"Hi Vidas, I’ve been wanting to learn this piece, so cool that you’ve got this. I like the pace that you’re going over it too, nice and slowly. Nice too be able to hear what you’re doing." (Dan)
Another student was studying BWV 533:
"Thanks Vidas, and thanks as always for doing the fingerings. It is helpful to see how somebody else solved the same problems, and your fingerings are often simply better than mine." (Ben)
About BWV 578:
"Thank you for your excellent videos and emails - they have really helped me improve my playing and given me more confidence. I practice on the organ as often as I can, but unfortunately that is not every day as I work full time and the church building is often in use in the evenings for other things, so even if there is access to the organ, I cannot play it or there would be complaints about the sound! I regularly play for Sunday services, weddings and funerals. Since I have subscribed to your emails and watched your videos, I have had many more compliments than I did before. Thanks again for sharing your wisdom and experience." (David)
If you are in a situation, like David, you can also try playing the organ without the stops on - silently - hearing the music in your head. This way you can save much time and use it when YOU want, not only when the church is empty. I do it all the time at St. John's church in Vilnius.
You can find these trainings here.