"I'm Not Alone" is a song by Scottish recording artist Calvin Harris, released as the lead single from his second studio album, Ready for the Weekend. The track was first played by Pete Tong on BBC Radio 1 as his "essential new tune" on 23 January 2009 and has been described as a slice of euphoric dance.

On 12 April 2009, the song debuted at number one on the UK Singles Chart, earning Harris his first solo number-one single on the chart and second overall following his 2008 collaboration with Dizzee Rascal and Chrome, "Dance wiv Me".

In 2010, Harris received a writing credit on Chris Brown's hit single "Yeah 3x", due to the perceived similarities between the two songs.

Harris said of this song: "The whole track's a light and shade thing, two styles put together. I find it quite hard to write a happy-happy lyric now, for some reason. I don't know why that is, to be honest with you. Maybe it's staying in a room for a huge amount of time on your own, and that's reflected in the lyrics!" The song is written in the key of E minor, and follows a chord progression of Em/D/Am/C.

"I'm Not Alone" debuted at number one on the UK Singles Chart on 12 April 2009 ― for the week ending 18 April 2009 ― knocking Lady Gaga's "Poker Face" off the top of the chart. It remained at the top position for two weeks, until it was dethroned by Tinchy Stryder's "Number 1" featuring N-Dubz. On 3 January 2010, "I'm Not Alone" re-entered the chart at number ninety-nine.

In the Republic of Ireland, the single debuted at number fourteen on the Irish Singles Chart on 9 April 2009, peaking at number four by its third week.

...
Wikipedia