force in the mid-1990s. Additionally, Mariah's sister Alison Carey had been diagnosed with HIV in 1988 when she was 27, an event that ruined their relationship and tore them apart. Carey has stated that she wrote the song hoping that all her fans that have lost someone could relate to "One Sweet Day" and maybe help ease the pain of the loss. Carey described the song as "[the] whole idea of when you lose people that are close to you, it changes your life and changes our perspective." Composition "One Sweet Day" is a "big" R&B ballad. It incorporates organ instrumentation and different contemporary grooves and beats into its primary arrangement, adding percussion and synthesizers as well, while incorporating "flourishes and harmonies" from both Carey and Boyz II Men. The song is set in the time signature common time and moves at a slow tempo of 64 beats per minute. It is written in the key of A major and features a basic chord progression of A–Dmaj9–A–Dmaj9–Gadd9, while the basic melodic line spans roughly an octave and a half from E4 to A5; the piano in the piece ranges from D2 to A5. The song contains choral lyrics written by Carey, who also arranged and co-produced the song alongside Walter Afanasieff. Author Chris Nickson complimented the song's instrumentation and arrangement, calling its use of synthesizers "wise" and "efficient." Additionally, he claimed Afanasieff's production and Carey's vocal and production arrangement helped the song's vocals and lyrical content flow together. The song finishes with the last chorus and coda in the key of B major. Reception and accolades "One Sweet Day" has been met with universal acclaim from contemporary music critics. AllMusic's Stephen Thomas Erlewine praised the song for its craft and writing, commenting that "[in] "One Sweet Day," a duet with Boyz II Men, Carey appeals to both audiences equally because of the sheer amount of craft and hard work she puts into her albums. Steve Baltin from Cash Box wrote, "This single could be thrown at the bottom of the 99 cents bin, buried under the Partridge Family and Starlite Vocal Band, and it would still find its way into the hands of fans. This is as big a guaranteed hit as anything that’s come out in some time". He added, "You will never find a surer bet than whether this song will make number one." James Masterton for Dotmusic