his absence Cluster recorded Zuckerzeit (1974), with Rother credited as co-producer. The band's second album Deluxe saw producer Conny Plank co-produce with a 16-track recording machine and mixing desk, and featured live drumming by Guru Guru member Mani Neumeier. Deluxe emphasized Rother's rock and pop sensibility over Cluster's more improvisational approach, which led to some creative tension between the members. Collaboration with Eno: 1976 After the release of Deluxe, Harmonia went back to touring until Roedelius, Moebius and Rother ended their collaboration in summer 1976. All three members started solo projects but rejoined as Harmonia in September 1976 when Brian Eno visited them in Forst for 11 days, living and recording with Harmonia before proceeding to collaborate with David Bowie on his 1977 albums. Eno brought along a four-track recorder and a VCS3 synthesizer. The material for Tracks and Traces was not released until 1997 because the tapes were long considered lost. Eno has stated that Harmonia was "the world's most important rock band" in the mid '70s, Eno had joined Harmonia once live in 1974, jamming with the group at The Fabrik in Hamburg. David Bowie considered Harmonia one of the most important and influential German bands of the era. Reformation: 2007-2009 Harmonia reunited in 2007 following the release of their album Live 1974, a recording of their concert of 23 March 1974 at Penny Station Club in Griessem, Germany. Rother, Roedelius and Moebius performed live as Harmonia for the first time since 1976, opening the Worldtronics Festival at the Haus der Kulturen der Welt in Berlin, Germany on 27 November 2007. Musician, writer, and rock historian Julian Cope places both albums in his Krautrock Top 50. The trio also toured and a new recording drawn from this period, Live 1974 was released on the UK-based Grönland Records label on 22 October 2007 and the San Francisco based Water Records label in the United States on 11 December 2007. Harmonia made their first live appearance in the UK on 18 April 2008, playing on the opening night of the Ether Festival in the Queen Elizabeth Hall at Southbank Centre, London. In July 2008, the band also headlined the final day of the Supersonic Festival in Birmingham. Harmonia further appeared at the All Tomorrow's Parties music festival in the UK in May 2008, at the Numusic festival in Stavanger, Norway, at an edition of ATP curated by My Bloody Valentine