"On the Eleventh day of Christmas.."

On the eleventh day of Christmas,
my true love sent to me
Eleven pipers piping,
Ten lords a-leaping,
Nine ladies dancing,
Eight maids a-milking,
Seven swans a-swimming,
Six geese a-laying,
Five golden rings,
Four calling birds,
Three French hens,
Two turtle doves,
And a partridge in a pear tree.

Note: I like this explanation of "Eleven Pipers Piping.."
At the big feasts held during the holiday celebrations the guests were often entertained by musicians, dancers, jugglers, etc. as well as singing and dancing themselves. Bagpipes and their younger cousins the musette (an instrument similar to a bagpipe but the air for the sound came from bellows rather than blowing into the instrument) were popular instruments for dance music. While we usually associate the bagpipe with Scotland, they were also a common instrument in France as well. Since Queen Elizabeth I was succeeded by the Stuart kings of Scotland, bagpipes and other aspects of Scots culture were common among the upper classes in England as were elements of French culture due to intermarriage of the English and French nobility.
The pipers referred to in the song would be the professional bagpipe musicians hired to entertain the guests with their music and provide music for dancing.

Image Note: This again was best image in my minds eye for this interpretation. Credit to 'Eventful Gifts and Hampers'