Hal An Tow is a traditional May Day song. The term “halan” means “calends,” or first of the month, and “tow” means “garland”. This is No. 135, under the title Helston Furry Dance, in Palmer's Everyman's Book of English Country Songs.
It has been sung by many folk groups and singers including Oysterband, the Waterstons, and the Albion Band. This version is sung by Tempest, an American Celtic band from the San Francisco area.
Lyrics (there are various sets of lyrics, so this is just one):
take the scorn and wear the horns it was the crest when you were born your father's father wore it and your father wore it too Robin Hood and Little John have both gone to the fair-o we shall to the merry green wood to hunt the buck and hare-o hal-an-tow, jolly rumbelow we were up long before the day-o to welcome in the summertime to welcome in the May for summer is a-coming in and winter's gone away what happened to the Spaniards that made so great a boast-o? they shall eat the feathered goose and we shall eat the roast-o God bless Aunt Mary Moses with all her power and might-o send us peace in England send peace by day and night-o hal-an-tow, jolly rumbelow we were up long before the day-o to welcome in the summertime to welcome in the May for summer is a-coming in and winter's gone away