Watch the I IV I V IV in G over G Pedal online guitar lesson by Brad Carlton from Guitar Lab: Vertical Soloing

Now we'll change positions for this progression in G major. The 10th position will be our choice and will produce the following forms: A form for the G chord, D form for the C chord, and the E form for the D chord. The pentatonics will be 3rd string root for the G, 2nd string root for the C, and 4th string root for the D. The G major scale which contains all three of these major pentatonic scales would be scale form IV.