"En karusell" was originally released in 1972 as a 7" single in Sweden which was sung in Swedish and also in Japan where the song was titled "En Carousel" and sung in English. The song was included as the A-side song and was credited to Björn & Benny. Future members of ABBA Agnetha Fältskog and Anni-Frid Lyngstad did backing vocals on the song but were not credited for their contribution.The B-side song on the Swedish release was titled "Att finnas till" and the B-side song on the Japanese release was titled "Lycka".

"En karusell" failed to enter Svensktoppen (a popular top ten chart for songs in Swedish) but the B-side of the single "Att finnas till" lay on that chart for three weeks.

The song was covered by Anita Lindblom in 1972 and In 1975 was covered by Birgitta Wollgård & Salut.

In English "Att finnas till" translates to "to exist".

On 29 March 1972, "En Karusell" was recorded in English at Metronome Studio in Stockholm, Sweden and was credited to Björn & Benny, Agnetha & Anni-Frid. This English version was titled "Merry-Go-Round (En Karusell)" for the Swedish market and titled "Merry-Go-Round" for other releases. "Merry-Go-Round" was included as the b-side song to the single "People Need Love" which was also released in 1972.

The single "People Need Love" was included on the album "Ring Ring" which was released in 1973 under Artist name Björn & Benny, Agnetha & Anni-Frid.

"Merry-Go-Round" made its CD debut on the 1994 "ABBA" compilation "Thank You For The Music (box set)" as track 5 on disc 4. The song also appeared as a bonus track on the 2001 re-issued and re-mastered album "Ring, Ring" under the artist name "ABBA".

The song was sampled in the Royce da 5'9" song Merry Go Round.

The basic aim of the "People Need Love" single was not to promote the quartet but to promote the "Björn & Benny" duo, which was the singing and songwriting partnership of the two men. All four individuals had other commitments and therefore were not considering forming a permanent group. An example of this is the crediting; the single in most of the territories is credited to "Björn & Benny, Agnetha & Anni-Frid". The women were simply guesting as backing vocalists on the new "Björn & Benny" single. However, the positive audience reaction was unexpected.

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Wikipedia