Scales

This is a 2.58 minute video response from DJ Phillips on Sep 15th, 2009

Question:

"I found this question on the site in the forum. Let's say I and a friend are playing together in the key of G. My friend is playing the G chord and he will play the I IV V progression. I am playing the pentatonic scale in G. When my friend changes chords, do I change the scale I am playing in or do I stay in G? I hope this question is clear. Thanks John"