and the improvisational skills of Blackmore and Lord. Said Lord, "We took from jazz, we took from old fashioned rock and roll, we took from the classics. Ritchie and myself...used to swap musical jokes and attacks. He would play something, and I'd have to see if I could match it. That provided a sense of humour, a sense of tension to the band, a sense of, 'what the hell's going to happen next?' The audience didn't know, and nine times out of ten, neither did we!" A second Mark II studio album, the creatively progressive Fireball, was issued in the summer of 1971, reaching number 1 on the UK Albums Chart. The title track "Fireball" was released as a single, as was "Strange Kind of Woman", not from the album but recorded during the same sessions (although it replaced "Demon's Eye" on the US version of the album). "Strange Kind of Woman" became their second UK Top 10 single, reaching No. 8. Within weeks of Fireballs release, the band were already performing songs planned for the next album. One song (which later became "Highway Star") was performed at the first show of the Fireball tour, having been written on the bus to a show in Portsmouth, in answer to a journalist's question: "How do you go about writing songs?" On 24 October 1971 during the US leg of the Fireball tour, the band was set to play the Auditorium Theatre in Chicago when Ian Gillan contracted hepatitis, forcing the band to play without him, with bassist Glover singing the set. After this, the rest of the US dates were canceled and the band flew home. In early December 1971, the band travelled to Switzerland to record Machine Head. The album was due to be recorded at the Montreux Casino using the Rolling Stones Mobile Studio, but a fire during a Frank Zappa and the Mothers of Invention concert, caused by a man firing a flare gun into the ceiling, burned down the Casino. This incident famously inspired the song "Smoke on the Water". The album was later recorded in a corridor at the nearby empty Grand Hôtel de Territet, with the exception of the music track to "Smoke on the Water". That was recorded at a vacant theatre called The Pavillon before the band was asked to leave. On recording "Smoke on the Water", Blackmore stated to BBC Radio 2: