I don't think that answered his question fully. I don't think he meant the harmonics of JP's solo during the intro in TCOT for example, and there are no harmonics (an overtone) during the "you won't find it here" part of Another Day.
What he is doing is droning an open note, kind of an Alex Lifeson influenced thing. He's playing often a suspended chord with the suspended chord note (the 2nd or the 4th, depending on what type of a chord it is) as the highest note and the open string and letting it ring while plucking the rest of the chord.
If there's every any dissonance, it's because he could be playing a chord with both the major 3rd and the 4th (not that common, as its dissonance is fairly horrendous) - or he's playing, like he does on TCOT, a major 7th chord with the major 7th and the octave right next to eachother and droning the octave. The major 7th creates some dissonance, but it's more soothing generally and is probably what is the "happy" dissonance you're talking about.
This might not make sense to you, and this probably doesn't answer the question.. but whatever.