<P> Despite their commercial popularity, the group were dissatisfied creatively; lead vocalist Bono believed they were musically unprepared for their success, while drummer Larry Mullen, Jr. said, "We were the biggest, but we weren't the best ." By the band's 1989 Lovetown Tour, they had become bored with playing their greatest hits . U2 believe that audiences misunderstood the group's collaboration with blues musician B.B. King on Rattle and Hum and the Lovetown Tour, and they described it as "an excursion down a dead - end street". Bono said that, in retrospect, listening to black music enabled the group to create a work such as Achtung Baby, while their experiences with folk music helped him to develop as a lyricist . Towards the end of the Lovetown Tour, Bono announced on - stage that it was "the end of something for U2", and that "we have to go away and...dream it all up again". Following the tour, the group began, what was at the time, their longest break from public performances and album releases . </P> <P> Reacting to their own sense of musical stagnation and to their critics, U2 searched for new musical ground . They wrote "God Part II" from Rattle and Hum after realising they had excessively pursued nostalgia in their songwriting . The song had a more contemporary feel that Bono said was closer to Achtung Baby's direction . Further indications of change were two recordings they made in 1990: the first was a cover version of "Night and Day" for the first Red Hot + Blue release, in which U2 used electronic dance beats and hip hop elements for the first time; the second indication of change was contributions made by Bono and guitarist the Edge to the original score of A Clockwork Orange's stage adaptation . Much of the material they wrote was experimental, and according to Bono, "prepar (ed) the ground for Achtung Baby". Ideas deemed inappropriate for the play were put aside for the band's use . During this period, Bono and the Edge began increasingly writing songs together without Mullen or bassist Adam Clayton . </P> <P> In mid-1990, Bono reviewed material he had written in Australia on the Lovetown Tour, and the group recorded demos at STS Studios in Dublin . The demos later evolved into the songs "Who's Gonna Ride Your Wild Horses", "Until the End of the World", "Even Better Than the Real Thing", and "Mysterious Ways". After their time at STS Studios, Bono and the Edge were tasked with continuing to work on lyrics and melodies until the group reconvened . Going into the album sessions, U2 wanted the record to completely deviate from their past work, but they were unsure how to achieve this . The emergence of the Madchester scene in the UK left them confused about how they would fit into any particular musical scene . </P> <P>--Brian Eno, on Achtung Baby </P>

Which is the cover of the band's 1991 release achtung baby