"The Melancholy Hill - it's that feeling, that place, that you get in your soul sometimes, like someone's let your tyres down. It's nice to break up the album with something a little lighter. It's good to have something that's a genuine pop moment on every album. And this is one of those."
The music video was released worldwide on 15 June 2010. It was originally made exclusively available via iTunes, but was uploaded to the band's official YouTube channel a few days later. A teaser for the video was released on 9 June 2010, and stills of the video were published on writteninmusic.com on 11 June 2010. The video begins with huge ocean liner M. Harriet under attack by two planes. A ship attendant finds Noodle in her room, offering to escort her to the lifeboats. She says nothing, but walks over to a briefcase containing a Tommy gun and walks down the hall past the attendant with the gun. The song begins with Noodle open firing at the two oncoming planes ( 2 Vought F4U Corsair's to be exact) that are attacking the ship. She manages to shoot one plane down but does not have enough time to shoot the other. The other plane drops a bomb on the ship. As the ship sinks, Noodle is shown to have survived and climbs into a lifeboat with only her guitar and some supplies. Later on, a gigantic Russel Hobbs lifts out of the water underneath Noodle's lifeboat. The rest of the video shows Murdoc Niccals, 2-D and Cyborg Noodle traveling through the deep ocean with a fleet of submarines, crewed by all of the collaborators that helped make the album, including Lou Reed, De La Soul, Snoop Dogg, Mick Jones, Paul Simonon, 2manyDJs and Gruff Rhys. As they travel, a swarm of "Superfast Jellyfish" are seen and inadvertently sucked into some of the submarines. The submarines then rise to the surface, where a large manatee is sitting atop a tall plateau. Murdoc spots the Boogieman leaning over the creature and, shocked by the sight, orders Cyborg Noodle to attack it. Cyborg Noodle pulls out a pump-action shotgun and shoots at the Boogieman but she misses, hitting his clothes. He grabs the manatee and dives into the ocean. When the fog behind the plateau clears, it reveals Plastic Beach.
"On Melancholy Hill" entered the UK Singles Chart at #133 on 28 June 2010, before peaking at #78 on 4 July 2010. After entering at #20 on the UK Dance Chart, the single peaked at #13 on 4 July 2010. On 26 January 2011, "On Melancholy Hill" entered the Triple J Hottest 100, 2010 at #42.