It was seen as Pink Floyd's first foray into space rock (along with "Interstellar Overdrive"), although band members would later disparage this term. The song opens with the voice of their manager at the time Peter Jenner reading the names of planets, stars, and galaxies through a megaphone, sounding like an astronaut over an intercom. A barely audible line 'Pluto was not discovered till 1930' can be heard in the megaphonic mix. Guitarist and vocalist Syd Barrett's Fender Esquire emerges and grows louder. At 0:19 a rapid beeping sound appears. At 0:26, Nick Mason's drum fills begin, and Barrett plays the enigmatic introductory figure. Keyboardist Richard Wright's Farfisa organ is mixed into the background. Barrett's incantatory lyrics about space support the theme in the song, mentioning planets Jupiter, Saturn, and Neptune as well as Uranian moons Oberon, Miranda, and Titania, and Saturn's moon Titan. Barrett and Wright provide lead vocals. Bassist Roger Waters' aggressive bass line, Wright's Farfisa organ, and Barrett's kinetic slide guitar then dominate, with Jenner's megaphone recitation re-emerging from the mix for a time.