The album was a commercial success, reaching number 4 on the Billboard 200, the band's highest-charting album in the US.[2] In the UK, the album peaked at number 6. The album is certified gold by the Recording Industry Association of America (RIAA) for 500,000 copies sold in the US. Following its release, Emerson, Lake & Palmer took an extended break from writing and recording.
The album was recorded in February 1974 at the Anaheim Convention Center in Anaheim, California during the group's 1973–74 world tour in support of their fourth studio album, Brain Salad Surgery (1973). Its title comes from the introduction to the show spoken by the show's Master of Ceremonies (UK disc jockey Pete Murray) and the opening line of "Karn Evil 9: First Impression, Part 2".
To record the album, staff and equipment were brought in from Wally Heider Recording in Hollywood, including a 24-trackmobile recording and a 40-input mixing console. Peter Granet, one of the engineers, called it "the finest recording experience I've ever had".[3] The band also used a 4-channel quadraphonicPA system on the tour. A quad mix of the album was released as a three 8-track tape set; a quad LP record edition was planned for release in the Quadradisc format, but was scrapped due to engineering issues in mastering, which prevented JVC, the manufacturer, from cutting a stable master to meet the format's specifications.
Most of the recordings on the album were first used for broadcast on the American rock music radio show, The King Biscuit Flower Hour. In 1999, these radio recordings were released on CD.
All but one of the tracks from the band's most recent album Brain Salad Surgery appear in versions nearly unchanged from their studio renditions, save for the insertion of a five-minute Palmer drum solo to climax "Karn Evil 9: 1st Impression" and a stripped-down rendition of the Lake ballad "Still...You Turn Me On" which appears along with an equally downsized "Lucky Man" in the middle of Lake's acoustic solo spot during an extended "Take a Pebble".
The "Tarkus" suite is the most transformed from its original 1971 recording, thanks to extended keyboard solos on "Stones of Years" and "Mass", the insertion of an excerpt from King Crimson's "Epitaph" at the close of "Battlefield", and a greatly extended rendition of "Aquatarkus" which features a lengthy quote from Dick Hyman's 1969 Moognovelty single "The Minotaur". Only two tracks from Trilogy, "The Sheriff" and "Hoedown", featured since the group had previously encountered great difficulty in reproducing other songs from the album without the use of extensive overdubs; the synth work on "Hoedown" is considerably more advanced than that of the studio original, while "The Sheriff" is played as part of a medley with "Jeremy Bender".
The only songs played on the 1973-4 tour which did not make it onto the album were the primary encore "Pictures at an Exhibition" (due to its already having been their first live release) and the occasional second encore "Rondo", a live version of which had highlighted The Nice's self-titled third album.
AllMusic gave the album a mixed retrospective review, saying that it "makes one realise how accomplished these musicians were, and how well they worked together when the going was good." They praised the set for including all but one song from Brain Salad Surgery, and particularly commended the performance of "Karn Evil 9" as being far superior to the studio rendition. However, they noted that unlike most live albums of the era, Welcome Back did not incorporate studio overdubs, limiting the band's ability to recreate moments from their albums and resulting in poor sound quality: "Even the most recent remastered editions could not fix the feedback, the occasionally leakages, the echo, the seeming distance – the listener often gets the impression of being seated in the upper mezzanine of an arena."[4]
^"Classifiche". Musica e Dischi (in Italian). Retrieved 17 October 2023. Set "Tipo" on "Album". Then, in the "Artista" field, search "Emerson Lake & Palmer".