In a recent interview with NME, the soulful Sam Smith dished out some details behind his hit song, "Stay With Me."

Along with two collaborators, Smith said it only took about 30 to 40 minutes to write what would become a tune that has been at the top of Billboard's Hot 100 for more than 20 weeks. "The song just flowed out of us so naturally," Smith said.

After the first few takes, though, the crew wasn't satisfied with what they had. That's when Smith had the idea that would take the song to the next level. In a large recording area, Smith went to different parts of the room and sung the "stay with me" and "all I need" lines, layering his vocals each time.

"I layered my voice probably about 20 times," Smith explained. "I stood in different parts around the room and would layer my voice more and more and more, harmonizing and that kind of stuff."

When he heard the playback, Smith was essentially listening to a gospel choir made up of himself. "And I remember nearly crying because the whole song suddenly made sense. That one touch just turned the song into...it just sounded so anthemic."

Plenty of artists would agree with the singer since the song has been covered by the likes of FKA Twigs, Charli XCX and Ed Sheeran. Smith has been hard at work since the June release of In the Lonely Hour.

Smith is currently on the road in support of the album, and the European leg of his tour has sold out.