Purple Haze

Context: Music critic William Ruhlmann describes "Purple Haze" as having "relentlessly driving, if relatively slow-paced underlying music, which provides a good platform for some of Hendrix's inventive guitar playing". Beginning with its dissonant opening and heavy use of distortion, Hendrix's techniques "all contributed to the dirty, raw, metallic, [and] angular sounds" heard in the song, according to Shapiro. The intro consists of the melodic interval of a tritone or diminished (sometimes called flattened) fifth. Historically, this dissonant interval has been referred to as diabolus in musica (literally "Devil in music") and was reputedly proscribed by papal bull during the Spanish Inquisition, because "to play it was like ringing Satan's doorbell". It is sounded during the first two measures by Hendrix playing a B on guitar against an E played by Redding on bass, followed by the respective octaves. Mitchell on drums comes in for the third measure, when Hendrix introduces the riff that piqued Chandler's interest, and Redding continues playing the octaves in E. After the riff, the verse sections begin, which Shadwick describe as "simplicity itself, consisting of just three chords": E7#9, G, and A. The E7#9, or dominant seventh sharp ninth chord, has come to be called the "Hendrix chord" by guitarists and was used primarily in rhythm and blues and jazz before Hendrix helped popularize it. He also used an unconventional fingering technique for the G and A chords. Because Hendrix used his thumb to fret the roots of the G and A chords on the sixth string, his fingers were left in a position to create different chord voicings. Instead of the usual G barre chord (G-B-G-B-D-G), a G5 (G-X-G-G-D-G) is sometimes played with the major third (B) being muted on the fifth string and replaced by the open third string (G). Redding follows the chord changes mostly by playing the root with occasional passing notes, while Mitchell heightens the tension with drum flourishes that accentuate Hendrix's vocal and guitar. Biographer David Henderson describes Hendrix's guitar tone as "at the razor edge of distort". However, individual notes are still clear, as well as the harmonically more complex chords, even with the use of extreme overdrive for the time. The tension is maintained until the guitar solo, which "arrives as something of a release rather than a further racking up of the atmosphere." It is also when Hendrix first introduces the Octavia, coupled with a Fuzz Face distortion unit. Whitehill describes the solo as "almost sound[ing] likes he's playing a blues raga. He starts out playing in the Mixolydian mode and then he goes right into the blues side. The Octavia has the effect of a sitar, kind of like Ravi Shankar meets B.B. King." During the song's outro, the guitar part recorded at 7 1/2  inches per second (ips) played back at 15 ips, is combined with the Octavia, further extending the guitar's upper frequency range. Henderson describes it as "an uncanny piercing tone that takes off, Eastern-sounding beyond the range of the guitar" and, according to Shadwick, "gives the impression that the guitar notes are flying off into the ether." CANNOTANSWER

Question: What else is important about the composition of the song Purple Haze other than the tension being maintained until the guitar solo?
Answer: E7#9, G, and A. The E7#9, or dominant seventh sharp ninth chord, has come to be called the "Hendrix chord" by guitarists