Watch the Chord Extensions Pt. 3 online guitar lesson by Brad Carlton from Guitar Lab: The Imaj7 IVm6 Progression
In this lesson, I'll demonstrate adding the 7 to each of the chords. There are two ways to locate the 7: It will always be a whole step higher than the 6 and a half step lower than the root. Knowing this enables you to take any chord voicing and modify it to include the 7.