Led Zeppelin II is the second album by the English rock band Led Zeppelin, released on 22 October 1969 in the United States and on 31 October 1969 in the United Kingdom by Atlantic Records. Recording sessions for the album took place at several locations in both the United Kingdom and North America from January to August 1969. The album's production was credited to the band's lead guitarist and songwriter Jimmy Page, and it also served as Led Zeppelin's first album to use Eddie Kramer as engineer. It was entirely recorded using the core band members, including Page (guitar), Robert Plant (vocals, harmonica), John Paul Jones (bass, keyboards), and John Bonham (drums).

The album exhibited the band's evolving musical style of blues-derived material and their guitar riff-based sound. It has been described as the band's heaviest album. Six of the nine songs were written by the band, while the other three were reinterpretations of Chicago blues songs by Willie Dixon and Howlin' Wolf. One single, "Whole Lotta Love", was released outside of the UK (the band would release no UK singles during their career), and peaked as a top-ten single in over a dozen markets around the world.

Led Zeppelin II was a commercial success, and was the band's first album to reach number one on charts in the UK and the US. In 1970, the album's cover designer David Juniper was nominated for a Grammy Award for Best Recording Package. On 15 November 1999, the album was certified 12× Platinum by the Recording Industry Association of America (RIAA) for sales passing 12 million copies. Since its release, various writers and music critics have regularly cited Led Zeppelin II as one of the greatest and most influential albums of all time.

Led Zeppelin II was conceived during a busy period of Led Zeppelin's career from January through August 1969, when they completed four European and three American concert tours. Each song was separately recorded, mixed and produced at various studios in the UK and North America. The album was written on tour, during periods of a couple of hours in between concerts, a studio was booked and the recording process begun, resulting in a sound with spontaneity and urgency through necessity. Several songs resulted from improvisation while touring, including during the instrumental sections of "Dazed and Confused", and were recorded mostly live in the studio.

The album used a wide variety of recording studios in the UK and the US. Some of these were lacklustre; one studio in Vancouver, credited as "a hut",had an 8-track set up that did not even have proper headphone facilities. A more favourable set-up was Mystic Studios in Hollywood, Los Angeles with Chris Huston engineering. Lead singer Robert Plant later complained that the writing, recording, and mixing sessions were done in many different locations and criticised the writing and recording process. "Thank You", "The Lemon Song" and "Moby Dick" were overdubbed during the tour, while the mixing of "Whole Lotta Love" and "Heartbreaker" was also done on tour. Page later stated "In other words, some of the material came out of rehearsing for the next tour and getting new material together."

Recording sessions for the album took place at Olympic and Morgan Studios in London, England; A&M, Quantum, Sunset, Mirror Sound and Mystic Studios in Los Angeles; Ardent Studios in Memphis, Tennessee; A&R, Juggy Sound, Groove and Mayfair Studios in New York City; and the "hut" in Vancouver. Production was entirely credited to Jimmy Page, with Eddie Kramerengineering. Kramer later said, "The famous Whole Lotta Love mix, where everything is going bananas, is a combination of Jimmy and myself just flying around on a small console twiddling every knob known to man."

Kramer later gave great credit to Page for the sound that was achieved, despite the inconsistent conditions in which it was recorded: "We cut some of the tracks in some of the most bizarre studios you can imagine ... but in the end it sounded bloody marvellous ... there was one guy in charge and that was Mr. Page." Page and Kramer spent two days mixing the album at A&R Studios. Full article