Watch the Islands online guitar lesson by Angus Clark from Play in the Style of David Gilmour
As you can hear in this example, intonation up high on the neck can be really challenging when playing with a slide and trying to be expressive. My second and third reps on this lick are better than the first. All of the usual slide rules apply: Mute your unused strings, mute behind the slide, get it right before you start using a huge vibrato to cover for your lack of accuracy. And most of all, stay in the groove!