U2 drummer Larry Mullen Jr. has praised producer Daniel Lanois for his interest in the more rhythmic aspects of the band. While early producer Steve Lillywhite emphasized Bono’s voice and the Edge’s guitars, Lanois focused on the more percussive elements, pushing Mullen to be more creative in the process.

One of U2’s most legendary songs came out of this partnership between Mullen and Lanois. After having co-helmed 1984’s The Unfortgettable Fire, the Canadian producer was back for what would become The Joshua Tree. Early on in the sessions, Lanois latched on to a rolling/stomping drumbeat that Mullen had created for a demo named “The Weather Girls.” Lanois wasn’t big on the rest of the track, but he liked the beat and encouraged the drummer to keep refining it.

The process continued, with Edge coming up with a gruff, acoustic guitar line that matched the blunt power of Mullen’s percussion. The guitarist also had a melody and a title: “I Still Haven’t Found What I’m Looking For.” Vocalist Bono took the idea and, with some guidance from Lanois, began to work with gospel themes.

“The music that really turns me on is either running toward God or away from God,” Bono told Rolling Stone. And yet, the singer described “I Still Haven’t Found What I’m Looking For” as “an anthem of doubt more than faith.”

Some of that doubt might have been a product of U2’s lack of experience at the time in terms of working with the distinctly American genre of black gospel music. Musically and lyrically, the band was trying to find themselves in the music of other people.

“I remember one of the problems we had, when you’ve got an old gospel tune, the problem is trying to bring it into the century, or into the moment you’re in,” Bono recalled in Classic Albums. “And so I think we did it by weaving together some overdubs.”

The Edge went at the tune in a number of different ways, eventually landing on a mix of arpeggiated chiming, rough rhythmic playing and an auto-panned guitar. Meanwhile, Bono sang the words at the absolute top of his vocal range, bringing out the plaintive qualities of gospel without sounding like an imitation. Co-producers Lanois and Brian Eno, as well as the Edge, multi-tracked backing vocals to strengthen the sound.

“I’ve always liked gospel music and I encouraged Bono to take it to that place,” Lanois recalled. “He’s singing at the top of his range and there is something very compelling about somebody pushing themselves. It’s like hearing Aretha Franklin almost. It jumps on you and you can’t help but feel the feeling.”

Indeed, fans couldn’t help but be drawn to the song, which – as U2’s second Joshua Tree single – became the band’s second No. 1 hit in the U.S., when released in May of 1987. Although “I Still Haven’t Found What I’m Looking For” has become a popular and important song for U2, it was just as notable for how it pointed the way forward during the sessions for The Joshua Tree.

“I was rooting around for a sense of the traditional and then trying to twist it a bit,” Bono admitted. “That’s the idea of ‘I Still Haven’t Found What I’m Looking For’.”

It became the idea for the entire album. Even visitors to the sessions would often get a quick performance of “I Still Haven’t Found…” as a taste for what U2 was trying to create on its new album. The song became a key building block for the band’s creative process as the Irish lads tried to merge American roots music, contemporary politics, deeply felt spirituality and a cinematic world view in the course of making their next LP.

Read More About 'Joshua Tree' Songs

"Where the Streets Have No Name"

"With or Without You"

"Bullet the Blue Sky"

"Running to Stand Still"

"Red Hill Mining Town"

"In God's Country"

"Trip Through Your Wires"

"One Tree Hill"

"Exit"

"Mothers of the Disappeared"

U2 Albums Ranked in Order of Awesomeness