The ‘happiest’ sounding of the modes, the Ionian is identical to the major scale, so it’s highly likely you’re already playing it on guitar. However, things really come alive when you approach Ionian as the ‘parent’ for all the other modes – but what exactly is a mode?
The best way to explain is with an example. The A Ionian mode (that's the same as the A major scale, remember!) contains these notes:
