to be like "legal drugs" that would create a trip where "you come out of the other end and you feel like you've been on some kind of a journey". The closing song on the album, "The Wanderer", features Johnny Cash on vocals, and was intended on being the "antidote" to the futuristic-sounding opener. "Zooropa" was written and recorded during the album's sessions at Windmill Lane Studios and The Factory Studios in Dublin, which took place from March to May 1993 between legs of the Zoo TV Tour. The song was created from two separate pieces of music. The first was a jam session recorded by the band in Dublin during the album's sessions. The second was a soundcheck the band had recorded a few years prior on tour in Australia or New Zealand that the Edge found while listening to cassette recordings of their soundchecks. Along with sound engineer Joe O'Herlihy, the Edge edited the best parts of the soundcheck using Sound Tools to create a song arrangement, which served as a backing track. The two-halves of the song were then edited into a stereo mix. Producer Flood created an atmospheric mix and then crossfaded it in with the song's "sombre, ethereal" introduction. The bass guitar in the intro was played by drummer Larry Mullen Jr. while the Edge was busy working on the album's guitar riffs. Synthesizer sounds were added by producer Brian Eno on a Yamaha DX7 keyboard, including a "squishy, mad-synth sound" to create a "dovetail" connecting the different segments of the song. The Edge later added guitar tracks, as well as additional sounds to the song using an EMS Synthi A synthesiser. Once the song was almost finished, the band had doubts about the first half's backing track. Having established an arrangement for the song, they performed it again in the studio and used the new recording for the first half, while using portions of the new performance for the second half. The band had originally intended on recording an EP during the sessions, but Zooropa eventually evolved into full-length album. "Zooropa" was one of five songs that were part of what would have become the band's EP, which also included "Babyface", "Numb", "Stay (Faraway, So Close!)", and "The Wanderer". Prior to the song's final title, it had the working title "Babble–Zooropa", as mentioned in a May 1993 issue of Hot Press, and was later