Mayer was due to perform with the British trio, but first Summers had to help him tackle a song he had struggled with himself ...

Over the years, John Mayer has proven his credentials when it comes to gear, with his best-selling PRS Silver Sky signature ...

Credit: Timothy Norris/Getty Images / Jim Russell John Mayer’s guitar rig and the secrets behind his otherworldly tone are, without exaggeration, the muse of countless guitar players the world over.