|"The Hardest Part", by Coldplay|
A piano-based ballad song, it begins with a two-note piano melody, followed with electric guitar lines, that accompanies a slow tempo drumming. It was released on 3 April 2006 as the fourth single from X&Y. The song was released as a radio-only song on United Kingdom radio stations. It appeared on the United States Billboard Hot Adult Contemporary Tracks chart and peaked at number 37. "The Hardest Part" also charted in both the Italian and New Zealand Charts.
The song was well received by critics. The track was complimented for its musical style. Regional singles were released in Canada, Europe, and Australia; a different version was released in Taiwan. Promo singles were released for the UK and US. The international version of the single was made available in the UK on 19 June 2006.