In the late 1960s, bands were expected to release more than one album a year, and they were usually happy to do so, since their income was derived more from live shows than from record sales, in the main. A new album also gave them the impetus to present new material and Zeppelin were no exception, although their debut album had been very successful.
There was pressure from all quarters to have another album ready by the end of 1969, and the band were equally motivated; their debut had shown the potential for their 4-way creative process and they had been playing a series of incendiary shows which were increasing their audiences in leaps and bounds. In America they had started in late 1968 opening for Vanilla Fudge, but before long they were assured headliners, with extended performances that became the stuff of legend.
Similarly, in Britain, they went from playing tiny pub venues like the Fisherman's Arms in Wood Green in March, to headlining the Pop Proms at London's Royal Albert Hall on June 29th. With a gruelling live schedule, there wasn't much time for recording, but studios were booked along the way and the band would dart in, lay down a track, and move on.
Often the song's inspiration would be from onstage improvisation, including the freeform section in the middle of Dazed And Confused; a riff would emerge, the band would remember it, and rush to record it as soon as was practical. Led Zeppelin II was finally to contain 9 tracks, recorded in at least 6 different studios, all sonically tied together by Jimmy Page as producer, with mixing overseen by new 'Director of Engineering' Eddie Kramer, who had impressed with his work on Jimi Hendrix's recent recordings.
Album sessions took place at Olympic and Morgan Studios in London, England; Mirror Sound and Mystic Studios in Los Angeles, California; and A&R and Juggy Sound in New York City, with apparently additional sessions in LA and Vancouver. The disparate tracks were given a cohesive mix at A&R Studios in New York, messrs Page and Kramer mixing the whole album in only a few days.
Led Zeppelin II was to be the breakthrough album for Zeppelin, especially in the US, where Atlantic Records had 400,000 advance orders. The album was released on October 22, 1969 and was certified Gold in the US by November 10th. The huge success of the million-selling US single Whole Lotta Love propelled the album to No. 1 in America, where it dethroned Abbey Road, twice. It took a little longer in the UK, but it climbed to Number One there as well in February 1970.