Blondie members Debbie Harry and Chris Stein (who were a couple) wrote the first version of this song in early 1974, shortly after they first met. They didn't have a proper title for the song, and would refer to it as "The Disco Song." Harry explained on the show Words and Music: "Lyrically, it was about a stalker who was pursuing me, and Chris saved me from him."
It wasn't until they recorded this song in 1978 that Stein came up with the title "Heart Of Glass." He didn't know that it was also the title of a 1976 German movie directed by Werner Herzog.
According to Rolling Stone magazine's Top 500 Songs, Harry and Stein wrote the song in their dingy New York apartment and keyboardist Jimmy Destri provided the synthesizer hook. The result brought punk and disco together on the dance floor. Said Destri, "Chris always wanted to do disco. We used to do 'Heart Of Glass' to upset people."
Debbie Harry (from 1000 UK #1 Hits
by Jon Kutner and Spencer Leigh): "When we did Heart Of Glass it wasn't too cool in our social set to play disco. But we did it because we wanted to be uncool. It was based around a Roland Rhythm Machine and the backing took over 10 hours to get down."
Chris Stein added, "We didn't expect the original to be that big. We only did it as a novelty item to put more diversity into the album."
Blondie re-recorded this in 1978 in a reggae style, but their producer Mike Chapman suggested reggae didn't sell in America. As Harry and Stein had a fascination with the disco sound that was then sweeping the country, so they adopted a sound that was an amalgamation of their New Wave background and Eurodisco.
Finding words to rhyme to "glass" that fit in a song can be... a pain in the ass.
In the last chorus, following "Once I had a love and it was a gas," Debbie Harry takes a different tack, singing "Soon turned out to be a pain in the ass." This is a key line in the song, since the singer has now realized that this relationship is more trouble than it's worth, and that her heart of glass might be more durable than she thought.
Unfortunately, American radio was generally ass-free at this time, so to ensure airplay stations were sent an edited version with the offending line replaced with "soon turned out I had a heart of glass."
The video for this song showed the band performing it in an empty discotheque, and was very popular, thanks to the many close-ups of Debbie Harry. Blondie was one of the few American bands that made videos in the years before MTV. They did so because they were very popular in Australia and Europe, and by producing videos, they could be featured on shows in those continents when they couldn't travel there.
The sound of the CR-78 drum machine was merged with that of drummer Clem Burke's real drums, which was no easy task in the analog age. Burke took his inspiration from the groove of one of his favorite songs: The Bee Gees' "Stayin Alive
The song's lyric turns the traditional heartbreak theme on its head. Debbie Harry explained in Q magazine: "I was tired of hearing girl singers write or sing about being beaten by love. So I said, Well listen, there are also a lot of girls who just walk away."
John Lennon once wrote Ringo Starr a postcard advising him to write more songs like "Heart of Glass." Debbie Harry told The Guardian: "It was totally wonderful knowing that."
The success of "Heart of Glass" launched Parallel Lines and Blondie into mainstream success, but it caused a lot of friction with some of their original fan base, which felt Blondie had sold out.
In a 1979 Los Angeles Times piece, Richard Cromelin observed, "'Death To Disco' T-shirts weren't an uncommon sight among the new wave audience that formed Blondie's first base of support. But, as it turns out, it's disco that's given life to Blondie."
Blondie guitarist Chris Stein responded, "We probably have alienated some of that original audience, but I really don't have sympathy for anybody that says we've sold out."
Keyboardist Jimmy Destri added, "These new wave kids think they know everything about rock and roll, but they won't accept anything else. They should listen to the album and realize that we haven't changed our direction that radically. We haven't become the Bee Gees."
The trouble didn't end there. The success of "Heart of Glass" created yet another problem for the band, because they weren't really a disco band. "We did a disco TV show and we were total outcasts," singer Deborah Harry told Cromelin. "Some other group tried to steal our guitars, they wouldn't give us a dressing room. So we might end up being total outcasts; from the rock 'n' roll crowd and the disco crowd. The rock crowd thinks we sold out and the disco crowd thinks we're punks."
An early version of this song called "Once I Had a Love (aka The Disco Song)" was included in the 2001 reissue of the Parallel Lines album.