Probably the most well-known piece of space themed classical music is Gustav Holst's The Planets. In this episode, we focus on the last movement of the suite, "Neptune," discussing how the timbre and harmony create its signature icy, watery,  mysterious soundscape. The suite was completed in 1918, but while selected movements were performed several times in the following years, it did not receive its full premiere with the "Neptune" movement until 1920. Despite the movement being an unusual choice for a finale, it was and still is extremely effective. We also discuss how the astrological inspiration for the suite led Holst to order the movements in the way that he did.   References Alan Leo, "The Art of Synthesis" Raymond Head, "Astrology and Modernism in 'The Planets'"