Watch the The I-V-IV-V Descending Bass online guitar lesson by Ravi from Guitar Lab: 30 Rock & Pop Progressions
This progression is similar to the previous one, but by playing the first V chord with another note from that chord in the bass, we create a step-wise descending bass line. In order to make the second V chord function that way, in the key of G play the D chord but with an F# in the bass by hooking your thumb over the neck, in the key of D play an A chord with your first finger and add a C# in the bass with your third finger, and in the key of C play a G chord with a B as your bass note played with your first finger (don't strum the sixth string at all). For the IV chord, the open strings will often enable you to continue the movement. For example, in the key of G you can play the C chord with the open E string in the bass, or in the key of C you can play the F chord with the open A string in the bass. In other cases such as in the key of D you can play the IV chord G with a B in the bass using your first finger on the fifth string, or in the key of E you can play A with a C# in the bass using your third finger on the fifth string.
Examples: Wonderful Tonight, All Out of Love