“He Won’t Go” (originally titled “What Is Love”) is the sixth track off of Adele’s sophomore album, 21. It was produced by Rick Rubin. The song was originally intended to be the last track on the album instead of “Someone Like You”. It was originally co-written by Adele and Paul Epworth under the title “What Is Love”.  Their version was originally intended to be put on the record, but Rick Rubin and Adele also did a version of the song that Paul liked better, and they ended up changing the name of the song to “He Won’t Go” and releasing the version produced by Rick Rubin.
This song was also the only song featured on 21 that was not included in the setlist for Adele’s Adele Live tour (as well as her performance at the Royal Albert Hall).  Despite this, it was performed during select dates on the tour, according to some fans. 
On September 23, 2015, Zac Brown Band uploaded their cover of the song on their YouTube channel. 
The song was mainly inspired by two friends of Adele’s that she had met after her first record, 19, was released. She had met them through her love of dogs. The male was a heroin-addict and had been making his journey to rehab. The couple’s bond had helped the male overcome his addiction, something that really touched Adele, who says that she is very proud of both of them, as the male has been “clean” for what is now over a year.  Adele spoke with The Sun, stating, “The first verse was about me and my ex but then became about two of my close friends who are a couple that became my lifeline when I came off tour. Two months after I met them, the boyfriend went into rehab for heroin addiction. I had no idea about his problem.” 
Adele revealed in an interview with Q Magazine that the song was conceived within the first seven hours of working with Paul Epworth, along with “Rolling in the Deep”.