Yes play the tune or follow the chords with the chord's pentatonic, that should give some structure to what you are doing.
C chord play the C Major pentatonic
Am7 play the A minor pentatonic
F play the F major pentratonic
G7 Play the G major pentatonic and add the b7.
To the beat of the song. String of notes is noise, some pauses in there helps a lot. Our ear wants to hear four note patterns if they (the patterns) end on a chord tone so much the better.
Follow the chords. Here is what Hal had to say about that.
http://www.youtube.com/watch?v=NehOx...feature=relmfu