Music Musically, "Planet Earth" has been described as
new wave and
disco, but more specifically
disco-punk and
post-disco.
Stephen Thomas Erlewine of
The A.V. Club characterised it as a blend of disco and
synth-punk, while the
Omaha World-Herald's Roger Catlin wrote that the song combines a danceable disco beat with
rock and
funk.
Annie Zaleski of
Salon commented that the song felt "like a response to trends — punk, disco,
Krautrock,
Bowie — not a direct replication of what had already been done". Len Righi of
The Morning Call described it as having a rhythm track reminiscent of
Talking Heads, and
Alexis Petridis of
The Guardian commented that the song had a "
Roxy Music-in-space" sound.
Rob Sheffield of
Rolling Stone wrote that the band aimed to merge the sounds of their two favorite groups
Chic and the
Sex Pistols, noting that the song features Chic's disco-inspired bass line and the punk attitude of the Sex Pistols. Members of the band, particularly the guitarist
Andy Taylor and the bassist John Taylor, cited disco-derived influences as key to the song's foundation. Andy Taylor saw the song's "essence" in
Rod Stewart's 1979 disco-rock song "
Da Ya Think I'm Sexy?", noting that it's synth-guitar hook shared the same scale, key, and opening chords (Dm7 and F) as Stewart's track, making the melody and counter-melody lines interchangeable. He also said in his autobiography that the song was "influenced by
German techno as much as it was by
punk and New York disco". "Planet Earth" opens with a sequenced keyboard part that Jeremy Allen of
The Guardian said "owed a debt of gratitude to
Japan's
Quiet Life". The song rests on what Zaleski described as a rhythmic foundation of John Taylor's "galloping bass" and the drummer
Roger Taylor's "stomping beats". Layered over this are "shimmering synths" from the keyboardist
Nick Rhodes and a "zig-zagging melodic line" from Andy Taylor, with these parts alternating in a "call-and-response" pattern. Throughout the track, occasional textures, such as "handclaps, sparkling synth ambience, bass curlicues, and a smoldering bridge — adds verve throughout". Zaleski wrote in
Diffuser that Rhodes' programming and the tension in his arrangements are central to the song's appeal, giving it a sound that feels "beamed in from outer space". Darryl Enriquez of the
Abilene Reporter-News commented that Andy Taylor's guitar playing "pops in and out of the song adding flavor and energy", and noted that the vocals and harmonies led by the lead vocalist
Simon Le Bon, together with Rhodes' keyboards, give the song a "feeling of detachment". John Taylor similarly recalled that Andy Taylor's "heavy-metal lead line, strangled through the Roland guitar synth", brought power to the track "under a dark light".
Themes and lyrics Critics described "Planet Earth" as having a
science fiction theme. According to the music journalist
Stephen Davis in his book
Please Please Tell Me Now, some fans believed that the song (with lines such as "there's no sign of life") was about the arrival of
aliens. However, Le Bon rejected the idea that "Planet Earth" has a science fiction theme. Instead, he described the song as being about waking up to the world and opening one's eyes to what is around them. He explained that the lyrics came from imagining what it would be like to see Earth for the first time, along with the idea of being born, "but at an age and with the kind of mentality where you can actually see what's going on". John Taylor said the lyrics felt new compared to what had come before, explaining that the song was "a celebration of youth, of the possibility of youth, about feeling good to be alive". He added that this approach felt fresh after several years of songs focused on themes such as hate and war. movement, which Duran Duran helped define. "Planet Earth" opens with the line, "Only came outside to watch the night fall with the rain", which Jim Zebora of the
Record-Journal described as the beginning of an "intriguing pattern of imagery". ==Release==