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 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.