The title translates approximately to "Summer Has Come In" or "Summer Has Arrived". The song is composed in the Wessex dialect of Middle English. Although the composer's identity is unknown today, it may have been W. de Wycombe. The year of composition is estimated to be ca. 1260.
It is sometimes called the Reading Rota because the earliest known copy of the composition, a manuscript written in mensural notation, was found at Reading Abbey; it was probably not drafted there, however. The British Library now retains this manuscript.
A rota is a type of round, which in turn is a kind of partsong. To perform the round, one singer begins the song, and a second starts singing the beginning again just as the first got to the point marked with the red cross in the first figure below. The length between the start and the cross corresponds to the modern notion of a bar, and the main verse comprises six phrases spread over twelve such bars. In addition, there are two lines marked "Pes", two bars each, that are meant to be sung together repeatedly underneath the main verse. These instructions are included (in Latin) in the manuscript itself.
The translation of "bucke uerteþ" is uncertain. Some translate the former word as "buck-goat" and the latter as "turns" or "cavorts", but the current critical consensus is that the line is "the stag farts".
This piece was parodied as "Ancient Music" by the American poet Ezra Pound (Lustra, 1913–1915):
Winter is icumen in,
Lhude sing Goddamm,
Raineth drop and staineth slop,
And how the wind doth ramm!
Skiddeth bus and sloppeth us,
An ague hath my ham.
Freezeth river, turneth liver,
Damm you; Sing: Goddamm.
Goddamm, Goddamm, 'tis why I am, Goddamm,
So 'gainst the winter's balm.
Sing goddamm, damm, sing goddamm,
Sing goddamm, sing goddamm, DAMM.
The song is also parodied by P. D. Q. Bach as "Summer is a cumin seed" for the penultimate movement of his Grand Oratorio The Seasonings.
Vernon Duke gently parodied and paid homage to the round with his song "Summer is A-Comin' In," with the verse making reference to "a troubadour / Way back in 1226." Each refrain of the song begins with the phrase "Summer is icumen in / Lhude sing cucu." The song has been recorded by Charlotte Rae (twice) and Nat King Cole, among others.
The song is also referenced in "Carpe Diem," by The Fugs on their 1965 debut album, The Fugs First Album.