1901

The writers credited are Thomas Pablo Croquet, which is Mars's credit name, Mazzalai, Brancowitz and Frederic Moulin, d'Arcy's real name. Phoenix and Philippe Zdar produced it, in 2008. Mars told Songfacts that Paris in 1901 was better than it is now, so the song is a fantasy about Paris. He told Express they wrote almost all of it in ten minutes but it took nearly a year to finish; it was one of the first songs made with Zdar, who pushed them to be modern. EQ Magazine describes wispy notes from a Yamaha Tenori-On through an AMS S-DMX delay and fuzzy Korg Trident chords. It was released on February 23, 2009 as a free download when the band's redesigned website launched, and Glassnote's Daniel Glass said SNL asked to book them weeks early after the leak.

It debuted at 90 on the Hot 100 in December 2009, peaked at 84 and reached number one on Alternative Songs on the chart dated February 20, 2010, its 31st week, the longest climb to the top since 1988 per Songfacts. It is platinum in the US. Pitchfork named it Best New Track and its third song of 2009, Rolling Stone placed it fifth, and the Village Voice's Pazz and Jop put it second behind "Empire State of Mind". They played it on SNL on April 4, 2009, on David Letterman in June 2009, and for La Blogotheque's A Takeaway Show at the Champ de Mars on December 3, 2009; it closed the Olympics ceremony on August 11, 2024. Birdy covered it in 2012, and it was used in Cadillac SRX advertisements in 2010 and in video games including Forza Horizon and NBA 2K13.