Let’s start working on some chord shifting by changing between G and C chords on each beat (Example 6). Allow your fingers to change as slowly as necessary for a smooth transition. If the open strings continue to ring out as you swap chord fingerings, don’t worry about it for now—it’s much more important to focus on getting your fingers into the right place at the right time. With practice, the amount of time it takes for you to make those switches will begin to decrease.
Excerpted From Rhythm and Strumming Basics: Working with a Metronome