Deductions about the music of the ancient Celts of the La Tène period and their Gallo-Roman and Romano-British descendants of Late Antiquity rely primarily on Greek and Roman sources, as well as on archaeological finds and interpretations including the reconstruction of the Celts' ancient instruments. Most of the textual information centers on military conflicts and on maybe the most prominent Celtic instrument of its time, the carnyx.
The Celts and Greco-Roman music
In 54 BC Cicero wrote that he "did not fancy" there were any musically educated people on the British isle. Independent of the validity of Cicero's remark, the situation was different for the Gallic regions. By the time of Augustus, musical education had widely gained ground in Gaul, as Iulius Sacrovir used the erudite Gauls as a decoy, after Sacrovir and Iulius Florus had occupied the city of Augustodonum during the Gallic insurrection in 21 AD. The Gauls took great pride in their musical culture, which is shown by the remark of Gaius Iulius Vindex, the Gallic rebel and later senator under Claudius, who shortly before the arrival in Rome called emperor Nero a malus citharodeus ("bad cithara player") and reproached him with inscitia […] artis ("ignorance of the arts"). However, Celtic music culture was spread inhomogeneously over Europe: Maximinus Thrax, the Thracian-Roman emperor of Gothic descent, annoyed his fellow Romans because he was unable to appreciate a mimic stage song.
The Carnyx
The carnyx (plural: carnyces; Greek: κάρνυξ—"karnyx"—or rarely: καρνον—"karnon") was a Celtic-Dacian variant of the Etruscan-Roman lituus and belongs to the family of brass instruments. It was an ſ-shaped valveless horn made of beaten bronze and consisted of a tube between one and two meters long, whereas the diameter of the tube is unknown. Archaeological finds date back to the Bronze Age, and the instrument itself is attested for in contemporary sources between ca. 300 BC and 200 AD. The carnyx was in widespread use in Britain, France, parts of Germany, eastward to Romania and beyond, even as far as India, where bands of Celtic mercenaries took it on their travels.
Gallic coins show the carnyx behind the head of the goddess Gallia or held by a chieftain, a charioteer or a Gallic Victoria. On British coins the instrument is seen swung by mounted Celtic warriors or chiefs. Roman coins, e.g. those heralding Caesar's victory over Gaul, depict the carnyx on Roman Tropaion as spoils of war. Other depictions are known from the Augustus statue of Prima Porta. In addition several instruments are illustrated on Trajan's Column, carried by Dacian warriors. The carnyx's most prominent feature is the bell, which was constructed as an animal head, either as one of a serpent, a fish, a bird, a wolf, a horse, an ass or a wild boar. The earliest depiction shows the head of a dragon and was found on Aetolian victory coins from the 3rd century BC, which commemorate the expulsion of the Gallic warriors, who had marauded the Delphi sanctum. Behn (1912) interpreted the many bell types as distinguishing features of the various Celtic clans and chiefdoms. Others have suggested a mythological component, which is the most logical explanation, since the Deskford Carnyx in Scotland was a sacrificial offering, of which the possibly dismantled head could have been the key element. Based on this independent development of the bell an attempt was made to derive the Etruscan lituus from the carnyx, but without success.