"Alone" is a song composed by Billy Steinberg and Tom Kelly. It first appeared via Steinberg and Kelly's 1983 pet project, I-Ten, on Taking a Cold Look. It was later recorded by Valerie Stevenson and John Stamos in their roles as Lisa Copley and Gino Minelli, on the original soundtrack of the CBS sitcom Dreams in 1984. American rock band Heart made it a number-one US and Canadian hit in 1987. Twenty years later, Celine Dion recorded it for her album Taking Chances.

Heart released the song as the first single from their ninth studio album, Bad Animals, in May 1987. Their version is a power ballad that begins with a piano line and a subdued vocal from Ann Wilson before exploding into an amplified hard rock and synth-led chorus. The song has been covered numerous times on American Idol. According to a Songfacts interview with Steinberg, Kelly (an experienced session singer) provided the high harmony parts on the record. "Alone" is Heart's biggest hit, spending three weeks at No. 1 on the U.S. Billboard Hot 100 that July. It ranked No. 2 on the Billboard Year-End Top Pop Singles of 1987, behind "Walk Like An Egyptian" by The Bangles. It is also their most successful single in the United Kingdom, where it peaked at No. 3 on the UK Singles Chart, so far as the band's only ever song to peak inside the UK Top 5; it is also one out of three UK Top 10 singles by the band. The song was also a huge global hit, reaching No. 1 in Canada, the top five in Ireland, Norway, and Switzerland, the top ten in Australia, Belgium and the Netherlands as well as the top twenty in Germany. The song's popular video featured the band in a synched live performance. An "unplugged" version of the song later appeared on Heart's 1995 album The Road Home. An extended version of "Alone" clocking in at 5:30 was released in Japan as the B-side to Heart's third single from Bad Animals, "There's the Girl". This "Long Version" is exclusive to this 3" mini-CD single, and not found on any other release.

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