Okay, so here we go!
Here's our first rhythm. It's a simple 3/4 rhythm which we're going to superimpose over a 4/4 groove in order to make a our phrases go over the bar line.
Getting the feel of 3/4 over 4/4 can be very tricky to achieve. Start by learning the 3/4 rhythm slowly and making sure it feels natural to you. Then, very slowly, with a metronome set to a slow tempo, try to play this 3/4 rhythm over a 4/4 click. You'll probably need to be very deliberate at first and concentrate hard to keep the rhythm correct.
Make sure you keep your foot tapping in time - this part is vital! It shows your internal pulse externally and will be a very good gauge for you as to how you're feeling the groove.
On the video, I start by playing the rhythm across a C Mixolydian Scale and then begin to improvise. You may notice during the improvisation I've doubled the speed of the rhythm. This is known in Jazz and Fusion as going 'Double Time' and is very common whilst improvising.
As a side note you would NEVER construct a solo using only this method. As you can hear, because of the exercises nature, it becomes very repetitive very quickly. However, if you practice these ideas you will become free from the constraints of bar lines when soloing and your phrases will be far more interesting and unique! Just check out Wayne Krantz for an example of how far this idea can go!