There's plenty that's genuinely old & strange, and I might venture the songs of Carmina Burana pre-date anything in respect of Pace-Egging, not only historically, but referencing as they do something even older in terms of the Secular Love Lyric and associated merry-making, most of which is pretty instinctive anyway. However, when I look at the product description for the book Rosie links to above I must admit to feeling more than a little nauseous. Here it is in full:

"See the blazing Yule before us". This is just one of the many ancient British folk songs we all know and love. Other tunes and symbols that tug on our memories have similar historical roots, hearkening back to a shared Pagan past. At one time interwoven into the spiritual fabric of everyday life, the dances, songs, and theatrical plays in the English folk tradition are now little known to most of the modern Pagan community. Reviving these vital traditions can bring new life to Renaissance festivals, neopagan rituals, and community events.Introducing the lively music and homegrown entertainment of times long past, this descriptive how-to is designed for twenty-first-century joviality. The songs, dances, and plays of old are explained in their mythical, seasonal, and historical significance and outlined for easy reenactment. Simple-to-follow instructions detail six dances including the popular Abbots Bromley Horn dance, six full scripts for dramatic performances of Mummer's Plays (folk plays of death and rebirth), and over thirty songs with lyrics and music. Kick up your heels, hold high your skirts, and make merry the year through.

So there they go again, the Pagan Community gleefully appropriating anything vaguely folkloric in the hope of menacing overtones of rampant fertility rites, ribald rudery, and rummy shenanigans in the newly-green wood. Mention of the Abbots Bromley Horn Dance reminds me of the old Folklore: The Abbots Bromley Horn Dance thread, with its links to the real thing:

http://www.youtube.com/watch?gl=GB&hl=en-GB&v=QPJW_FltI74

and various reimaginings thereof, such as:

http://www.youtube.com/watch?v=GKN0j4b9oU0.