Not a great deal of literature survives from the Anglo-Saxon period. Two well-known pieces are Beowulf and "The Seafarer."
The Anglo-Norman era represents the period after the Normans invaded England under the leadership of William the Conqueror. The language of the nobility was French. Perhaps the stories most famous from Anglo-Norman England are those of King Arthur and The Knights of the Round Table.
The Anglo-Saxon period was a violent time. A man was respected if he was a brave warrior. In Beowulf, the hero of the story (Beowulf, a Geat) comes from his land to join Sanish King Hrothgar to battle the man-eating monster Grendel. Because of the frequent attacks visited upon Hrothgar's mead hall, the mood from the beginning is dark. We also might imagine unfriendliness on the part of Hrothgar's men, who are suspicious and frightened when Beowulf arrives to help. (Raiding tribes often attacked other tribes to gain lands, etc.)
In Chapter Eight of Beowulf, Unferth the son of Ecglaf speaks in an insulting and unfriendly manner to Beowulf:
UNFERTH, THE SON of Ecglaf who sat at the feet of the Scylding's lord, spoke quarrelsome words. The quest of Beowulf, that noble mariner, galled him greatly, for he always begrudged other men who might achieve more fame under heaven than he himself.
His words are not well received by the noble Beowulf who, in return, challenges Unferth:
Beowulf, son of Ecgtheow, spoke: “What mighty things you've just said of Breca and his triumph, my dear Unferth, while you're drunk with beer!
This exchange from Beowulf shows Unferth's unfriendliness. However, on the whole, the tale is made up of promises of fealty, stories of valor, the suffering of loss, and reverence to God. It is very different in nature than the Anglo-Norman song "Sumer Is Icumen In" also known as "The Cuckoo Song" or "Summer Canon."
The text of this song you have mentioned is from the 13th Century. It is a round. It is believed to be the first English song.
It's important in musical history because at the time the Church was singing in Latin, the Royal Courts in French and this is the first piece of English music...
It reads as follows:
Summer has come in,
Loudly sing, Cuckoo!
The seed grows and the meadow blooms
And the wood springs anew,
The ewe bleats after the lamb
The cow lows after the calf.
The bullock stirs, the stag farts,
Merrily sing, Cuckoo!
Cuckoo, cuckoo, well you sing, cuckoo;
Don't ever you stop now,
Sing cuckoo now. Sing, Cuckoo.
Sing Cuckoo. Sing cuckoo now!
This song is friendly as it describes the gentle behavior of animals and plants—nature being so different than the lives of warring men. It speaks to the seeds growing and plants blooming. The time of year is the spring. It is also a period of new life seen with the birth of the lamb and the calf. The song is a round, which also gives a sense of "happiness" or friendliness in that several groups join together to complete the song in its entirety.
Perhaps the clearest contrast of the unfriendly nature of the Anglo-Saxons and the friendly nature of the Anglo-Normans is found in Gawain and the Green Night.
The introduction of the story relates how King Arthur and the Knights of the Round Table gather to celebrate Christmas. The mood and manner of the holiday celebration permeates the hall. The sense of friendliness one gathers from this tale comes from two things that Arthur practices all year long:
But Arthur would not eat till all were served…
And also another matter moved him so,
that he had nobly named he would never eat
on such dear days, before he had been advised,
of some adventurous thing, an unknown tale,
of some mighty marvel, that he might believe,
of ancestors, arms, or other adventures...
First, even being the most powerful person at court, Arthur would not eat until everyone else had been served. He also would not eat until someone had shared a tale of adventure, amazement, battle, etc.
In that Arthur puts others before him is a gesture of friendliness and goodwill, and the mood is quite different than that of Beowulf, but is in keeping with "Sumer Is Icumen In."