The band Trúbrot from Iceland was formed in 1969 as a supergroup made up of members from the well-known local bands Hljómar and Flowers. After their debut album with the US singer Shady Owens and various line-up changes, they travelled to Denmark as a quartet in 1970. The line-up consisted of Gunnar Þórðarson (guitar, flute, vocals), Magnús Kjartansson (piano, organ, vocals), Rúnar Júlíusson (vocals, bass) and Ólafur Garðarsson (drums, percussion). They spent around a month in Copenhagen recording their second LP, Undir Áhrifum (Under Influence) at Wifos Studio in Copenhagen, under the direction of the studio owner and sound engineer Philip Foss.

In contrast to their first album, which contained various classics from the 1960s in Icelandic versions, here they ventured into the territory of progressive and psychedelic rock, with almost all the songs sung in English. Their self-produced album was released by Parlophone that same year, just like their debut exclusively in Iceland. It features magnificent, polyphonic English male vocals in the style of Crosby, Stills & Nash, accompanied by acid rock with some psychedelic pop-rock influences. Outstanding arrangements and a varied use of organ and powerful guitars characterise the work, which is heavily influenced by the British underground scene. The record was voted the best album of 1970 in Iceland and is now a very rare and sought-after progressive rock LP.