One hundred years ago, English composer Gustav Holst began work on what would become his most famous work -- The Planets -- which he would complete in 1916. The work is a suite for orchestra, with each movement being named after a planet in the Solar System. At the time of its writing, the existence of Pluto was unknown; and so Neptune was the most remote planet to be included in the work.
Holst died in 1934, not long after Pluto's discovery in 1930 by astronomer Clyde Tombaugh at the Lowell Observatory in Flagstaff, Arizona. With the official count of planets expanded to nine, I always thought it was unfortunate -- maybe even a little sad -- that Holst was not able to "complete" his suite by adding in a movement named after the planet Pluto. But fast-forwarding about 75 years, Pluto's status was reduced to that of a dwarf planet by the International Astronomical Union.
So maybe Holst didn't just run out of time after all. Perhaps he just didn't consider the tiny newcomer to be worthy of sitting alongside such lofty celestial bodies as Mars and Jupiter!