The year 1975 saw a turning point in Kraftwerk's live shows. With financial support from Phonogram Inc., in the US, they were able to undertake a tour to promote the "Autobahn" album, a tour which took them to the US, Canada and the UK for the first time. The tour also saw a new, stable, live line-up in the form of a quartet. Hütter and Schneider continued playing keyboard synthesizers such as the Minimoog and ARP Odyssey, with Schneider's use of flute diminishing. The two men started singing live for the first time, and Schneider processing his voice with a vocoder live. Wolfgang Flür and new recruit Karl Bartos performed on home-made electronic percussion instruments. Bartos also used a Deagan vibraphone on stage. The Hütter-Schneider-Bartos-Flür formation remained in place until the late 1980s and is now regarded as the classic live line-up of Kraftwerk. Emil Schult generally fulfilled the role of tour manager.