If you play improvised American music (“jazz” if you will) then at some point you need to tangle with a John Coltrane tune called “Giant Steps.” On the seminal recording by Coltrane it is played at about 300 beats per minute – smokin’ fast – and involves angular key changes that are a minor third apart, hence the “giant” steps of harmony. It isn’t the most difficult piece in the world, but it is certainly an achievement to be able to improvise over it coherently and at full speed.
When you are Pat Metheny, one of the world’s top composers and a legendary innovator on the guitar, you can play Giant Steps at light speed in any style. This is what makes his decision to play it at a relaxed tempo all the more interesting an artistic choice. He doesn’t need to show off, instead letting the interesting harmonic shapes of the tune come through. It’s inspiring and still more than a little challenging to emulate.