Expressions
The Celts are a people of many virtues, but moderation is not one of them. The ancient Celts lived their lives at a fast pace, and when their daily chores were done, they did not lay their hands idle. Leisure was equal to entertainment, and spare time was always full of games, sport, dancing, song and music, often connected with extravagant feasts. All products were endowed with rich decorations to the delight of the archaeologists of our time. The Roman writers tell us that music accompanied the Celts in all their tasks, and that a rich variety of instruments was available. This music is of no help to the archaeologists, but it is the one cultural trait that has survived best and has retained its mark of Celticness as far as our own time. Usually, it was accompanied with song, and it was the chief task of a class of professional singers called bards to maintain the old songs and compose new ones, to provide entertainment and enlightenment in peaceful times and encouragement in battle. The bards were more than craftsmen, they were as highly respected as druids and kings and played important roles in social life. Their music itself didn't appeal so much to the Roman writers, it seems it was too wild and barbaric for them.
Just what this music was like is hard to imagine. Celtic music today has many wild melodies with a fast pace, often for dancing, and maybe if the the Roman writers could hear it, it would sound just as wild and barbaric to them as the Celtic music of their own time did. But in addition to the wild dance music, there are slow, lyrical pieces as well. Probably the ancient music was very, very different from the Celtic music of today. What it was like, we can only guess, but its quality was very likely at least equal to the other Celtic cultural expressions, and most probably, it would have pleased an open modern ear greatly. A typical trait of today's Celtic music is the use of the pentatonic scale. Particularly in Wales, there is also some diatonic music, but this can be due to continental influence - when England was conquered by the Tudors, Wales and particularly Welsh upper class culture were strongly linked to the rest of Europe. The pentatonic scale is also called the natural scale, because it contains the tunes that can come out of a flute without holes. It is common in the folk music of northern Europe and northern Asia as well as America. Another typical trait of Celtic music is polyphony, the various instruments supplement each other and the song with their own melody lines. The honour of introducing polyphony to European mainstream music is often given to John Dowland, an English composer of the 17th century. But Dowland (originally Dolan?) probably came from Ireland - in the 15 and 1600s, there was a strong campaign to exterminate the Irish bards, who encouraged resistance against English suppression. Some of these probably escaped to England and were instrumental in the rich flowering of the music in the Elizabethan age, ("exiled forever, let me mourn" - one well known Dowland quote). But this could mean that the Irish music at this time already was polyphonous, and for all we know, this could have been the case in the Roman era as well, at least the rich variety of instruments is supportive. Thus, one good guess is that the ancient Celtic music was pentatonic and polyphonous. But how can we ever know?
The classical writers have quite a different respect for the verbal achievements of the Celts than for their music. They were famed for their eloquence, and a substantial number of Celtic speeches are copied in historical works. It has been suggested however that some or even all of these speeches may be fake or at least elaborated by the writers - the barbarian orator is quite a cliché in adventure stories of that time. Latin literature, particularly the medieval brand, contains a number of obvious such fakes. At the very least, the speeches had to be translated, and then, the writer had to deal with the temptation to adapt them to his own writing style. But the Celts may in fact have been the actual model for this cliché, we have other indications of their preoccupation with verbal art. The Bards are one, and the art of storytelling has had a unique position in all Celtic lands up to and including our own time, although it could be objected that the Celtic fame for eloquence of old may have been the very origin of this tradition. After the Roman conquests, the most ambitious Celtic storytellers started writing in Latin, and soon achieved great fame. It is a not sufficiently well known fact that some of the greatest Roman writers like Virgil, Livy, Catullus and Varro were from Cisalpine Gaul, and from Celtiberia, we have Seneca, Lucan and many others. These writers formed a Celtic school of writing, focusing more on epic and fantasy than the classical school, a feature very typical for later Celtic literature as well. But to some extent, they were scorned by the more traditional writers, who saw their efforts as somewhat uncouth and barbaric. Some of these writers may have been colonists of Roman origin, at least Seneca used the classical rather than the Celtic style, but again, the wish to please the classicist Roman audience may have been his motive.
No literature in Celtic languages is known from antiquity, except some scattered verses scribbled on daily utensils and that sort of thing. This is because the Celts despised the art of writing. The druids and bards learned their knowledge by heart, it was their property, their secret and their livelihood. They thought that people in the civilized countries ruined their memory by relying on books. The Celtic mentality is strongly individualistic, and the idea of knowledge and capabilities being personal is important to them. In their religion, the head was regarded as particularly sacred. Heads of renowned leaders were thought to have protective power, and famous warriors would preserve the heads of their most formidable enemies and display them to their guests, sometimes in richly decorated boxes.
As the Celtic culture spread and made contact with the town dwellers, they adopted Greek writing for practical purposes. The Greek colony Massalia (today's Marseille) in southern Gaul was influential in that area. Later, when the Romans grew in power, Latin letters were used as well. The insular Celts were less exposed to such influence, but in Ireland, they developed a writing of their own, the Ogham, completely unrelated to other systems. However, none of these systems conveyed any literature, they were used on coins, monuments, for decoration of artifacts and little else. Until Christianity arrived and broke down the old taboos. Monks wrote down some bardic tales, and many of them contain elements that originate in antiquity. Names and places from the conflicts between Romans and Britons can be identified, but the events are strongly distorted. Britain was conquered following the invasion of Claudius in 43, when Cunobelinos, who ruled as high king of Britain from his court at Camulodunum (today's Colchester) and had kept the isle outside Roman influence for more than 30 years, had died, and Adminios, one of his sons, asked the Romans for help to gain the throne. This treason, which did not help him much, along with the successful reign of his fater and the heroic and successful resistance of his brother Caratacos, which came abruptly to an end when he was betrayed by Queen Cartimandua of the northern Brigantines with whom he had sought shelter, was transferred to the later resistance against the Anglo-Saxons and became a legendary cycle of immense popularity which gave rise to the modern secular literature when it spread outside the Celtic area some 1000 years later. Over the centuries, mythological and historical events and personae were added, augmenting and replacing the older ones until we arrive at the tales of King Arthur and the knights of the round table.
Since then, Celtic storytelling has been triumphant with the aid of the written word. The Celtic languages have a rich literature, and the ones in the languages that have taken over from Celtic ones some places are perhaps even richer, particularly the English one. Well known is the unique position of Irish literature. But storytelling is more than just written words sold in bookstores. It was and is highly esteemed throughout the populace, and those who have stories to tell soon get an audience. Celtic legends and fairy tales have their own flair, they have wandered wide past the Celtic borders and other stories coming the opposite way were re-told with a Celtic twinkle. Songs are storytelling too, and Celtic songs lately have received a huge international audience.
The cultivation of language has been important for the Celtic peoples from the beginning. With their passion for poetry and storytelling, it was important to develop the language to make it more melodious and a better tool for communicating those thoughts that were foremost in their minds. Songs in Celtic languages are sometimes a blessing to the ear even if you don't understand the content, and if you take the trouble to learn one of them, you will get a means to express many things that are difficult in other languages, particularly otherworldly things. Other countries where Celtic languages have departed long ago, like France (excepting Brittany) and England, also have cultivated their language strongly, and much great literature has been produced in those languages. One may claim that the Celts are partially responsible for this, there's noone denying you that at least.