Watch the C7 F9: Pt 8 online guitar lesson by Brad Carlton from Guitar Lab: I7 to IV7 Vamps

The voicings of the C7 chords in examples 25 through 28 were drop two voicings. These are practical on the guitar because you don't have to stretch as far. Example 30 takes the same chords that you had in example 26 but plays them in close voicings.