I have purchased Griff's terrific new course modes unleashed. And, I'm really just in the memorize the modes process. But, I've also created my own jam track for The Weight in A major. So, I'm practicing all the modes over my jam track and only the Ionian works. I do recall Griff mentioning that only one will work. So, it seems that the 1st mode, the Ionian mode works over the track and over the entire chord progression (A, C#min, D, A). Can anyone tell me why?