This is a simple introduction to using perfect fourths over a Major 7 (#11) sound. By stacking four perfect fourths off of the 7th degree, the 6th degree, the #11 degree and the 3rd degree of the Lydian scale (Maj #11), you learn four common places where perfect fourths function well this common sound. Also notice that you can play perfect fourths from the #11 clear to the 5th (6 notes in a row) while staying within Maj7(#11). This exercise is played around the circle of 4ths starting with concert CMaj7(#11). Keep in mind you could play just one group of stacked fourths or play them in a minor context (CMaj7#11 = A-7) or dominant context (CMaj7#11 = D7 or Dsus7). I would encourage you to try and sing this melody slowly over a drone while visualizing the notes and fingerings.