Watch the Rocking Chair: 7 online guitar lesson by Chris Buono from Guitar Cubed
Even with the counterpoint action going on in Guitar 1 there’s still an overall underlying tonal center here and that’s Am. If there was any doubt Guitar 2 surely reiterates that fact with it’s gutsy albeit brief riffing. Playing the b3rd and 5th (C-E) of an Am chord on the 3rd and 2nd strings, Guitar 2 comes crashing down on a b7 to root hammer-on on the fourth string on the downbeats of bars 2 and 4. In bars 5-6 you get the same deal, just a whole step down for a change to bvii (Gm).
In both instances the diad played on the G and B strings are pulled to the floor by the fret hand 1st finger for some rock 'n roll approved pitch mod. Before slamming down on the b7 to root hammer-ons, check out the descending rake that’s employed for added 'tude that precedes the downbeat. If you listen (or watch) closely there’s actually a second rake that comes form above into the 4th string hammer-on, too.
With all this talk of vibrato it’s important to note the importance of holding back and waiting for just the right time to apply it. After every hammer-on is played at the downbeats of bars 2, 4 and 6 it’s not until a little after the downbeat of 2 do you hear the vibrato start to kick in. Even then it’s subtle and gets a chance to build. That’s the real deal, guys. This is another way to take advantage of that precious commodity known as space.