Purple Haze is a hugely popular Jimi Hendrix song, released as a single on his album "Are You Experienced" in 1967. Like many other guitar players, this was one of the first Hendrix songs I ever tired learning because of its powerful opening lick. The cool thing about the opening is that it uses a flat fifth otherwise known as a tritone. Tritones are the most dissonant sound in western music, and Hendrix was all about creating an atmosphere or musical environment. Using a tritone gave him a great way to create a hectic and tense feeling in the intro. Just a fun fact, tritones used to actually be banned for several hundred years in Europe because they were said to conjure the devil with its sound, and at the time music was played for the church. The licks used in this song are fairly simplistic, revolving around a sort of pentatonic shape that moves diagonally across the fretboard instead of straight up and down or simply changing strings.