On June 6, 2005, Coldplay released their third studio album X&Y. It brought along with it songs that would later become Coldplay classics like “Speed of Sound”, “Talk”, “Fix You” and “The Hardest Part”. It sold 8.3 million units in its first year alone, making it the best selling music album of 2005. In the last decade and a half, it has sold over 13 million copies worldwide. As the album celebrates 15 years, go deep and learn seven things you didn’t know about the album below.

1. The album contains a hidden track called “Till Kingdom Come”. It was labelled as “+” on the back of the CD case. It was originally written as a duet for frontman Chris Martin to perform with Johnny Cash, but Cash passed away before he could record it. When played live, the band often combines the song with Cash’s “Ring of Fire”.

2. The song “Speed of Sound” was inspired by Martin’s then-infant daughter Apple and musician Kate Bush. “That’s a song where we were listening to a lot of Kate Bush last summer, and we wanted a song which had a lot of tom-toms in it. I just had my daughter up also, and was kind of feeling in a sense of awe and wonderment, so the song is kind of a Kate Bush song about miracles.” The drumbeat pays tribute to the beat in Bush’s 1985 song “Running Up That Hill”.

3. “The Hardest Part” was also inspired by a band Coldplay admired – R.E.M. The song pays tribute to R.E.M. frontman Michael Stipe. When asked why, Martin said, “I’ve lost all respect for fame, but I haven’t lost all respect for respect. So the one great thing about being famous is that I get to meet people who I respect. Our relationship is akin to a dog and its master. I’ll always look up to him.” The band call the song their version of “Losing My Religion”.

4. Chris Martin intended to write “Fix You” using a church organ. After the instrument became unavailable, he used an old keyboard that his father-in-law gifted his then-wife Gwyneth Paltrow. He was the first one to ever plug it in. After writing it, Martin knew the song was “probably the most important song we’ve ever written”.

5. Taking inspiration from another band, Coldplay wrote “Talk” as a tribute to Kraftwerk. The band originally recorded a different version of it, but scrapped it before anyone got to hear it. They were skeptical of adding it to the album and it ended up being the last song to make the cut.

6. The album’s artwork was designed by graphic design duo Tappin Gofton using the Baudot code, an early form of telegraph communication using a series of ones and zeros. The code was first developed in 1870 by Frenchman Émile Baudot.

7. X&Y tied with The Black Eyed Peas’ Monkey Business for International Album of the Year at the 2006 Juno Awards. It was also nominated for Best Rock Album at the 48th Grammy Awards, but lost to U2’s How To Dismantle An Atomic Bomb.

Filed under: Coldplay, X&Y