Hey Ron! Glad you're digging the lessons.

B7 is absolutely a great substitution here. It's a very common choice for country songs that feature a progression that uses Imajor, IVmajor, and Vmajor chords. Substituting a V7 instead of the straight V chord is very common.

I taught the lessons on the site based on what I was hearing off the recorded version. After the key change, you'll notice sometimes I teach a straight B chord, and other times an A/B chord, which is an A chord with a B note as the root. The A/B is another common substitution that can be used, and I was hearing it clearly on the recorded version.

But of course, everything is open to personal interpretation, so I welcome any embellishment or any substitutions that you think sound good. Clearly, George and his band have no problem using the B7, so go for it!!

thanks!!
Mike