From Barddas Vol II (my emphasis):
1. There are three Banded Bards.
The first is the Primitive Bard, or Poet, whose function and art are to poetize, and to preserve the memorial of every thing that is commendable in man or deed–to celebrate in song every thing that is commendable and good, as would be fitting in respect of what is meritorious and deserving–to teach in song every thing that is good in respect of doctrine and usages, and to maintain the memorial and teaching of the art of song, and all the privileges and usages which have been conferred upon the Bards of the Isle of Britain, and to teach them in methodical song, according to the proper art of vocal song of the Bards of the Ancient Cymry; And it is his duty to arrange and systematize matters, according to the privileges and usages of the Ancient Cymry, in every Chair and Eisteddvod, and Gorsedd of vocal song; it is incumbent upon him also to preserve and maintain the Cymric language free from degeneracy and corruption, and to teach it correctly, according to its quality and original and proper arrangement.
The second is the Herald-bard, whose office and art are memorial, instruction, and history–to symbolize good and laudable deeds, and to record in book and writing the genealogies and descent of the nation of the Cymry, their privileges and usages, so that they may be known, lest there should happen to the nation of the Cymry that degeneracy and ignobleness which impoverish the descent and privileges of a nation, and hence ensue non privilege and false privilege, and every lack of system, as has been the case with those unlearned nations, among which neither Awen from God, nor Bards, nor Bardism proceeding from that Awen, have been found. It is his duty to learn to read and to write the Cymric language, and to commit it to book and song properly and correctly, and to know the privileges and usages of the Bards of the nation of the Cymry, with their nature and essence. He ought also to impugn all ignobleness, all lack of privilege, all false privilege, and all illegality and disusage, lest the nation of the Cymry, their privileges and laudable usages, their language, innateness, and celebrated antiquity should suffer corruption.
The third is the Post-bard, whose art is vocal song according to the inventive instruction and skilful art of the later Bards, and to impart instruction in every science, wisdom, arts, and good and laudable usages, and to systematize new sciences according to kind, number, time, place, occasion, and dignity.
And this is the distinction between the Primitive Bard and the Post-bard: the Primitive Bard ought to bring with him what has been behind him from old ages, and the Post-bard ought to call to him what he sees before him; whilst the Herald-bard arranges these things according as the advantage, requirement, nature, essence, time, and dignity of them may demand; and to bestow instruction, sciences, wisdom, art, dignity, and honour out of them upon the nation and country of the Cymry, as befits what is good and praiseworthy.
10. There are three disciplinary degrees attached to vocal song and Bardism, namely: the first is a probationary Disciple; the second is a pupil Disciple; the third is a master Disciple.
A probationary Disciple ought to know the system of syllables and sentences, according to the Books of the system of metricities, and how to arrange the metres of domestic song, for that belongs to the discipline of vocal song, and to sing in five of those metres poetically according to the opinion of a master of song, who shall say upon his word and conscience that he is competent to be a poet; he ought also to know the laws and usages which relate to his discipleship.
A pupil Disciple ought to know, in addition to what a probationary Disciple knows, the system of metres and resumptions, and to be able to sing in the nine primary metres, and to exhibit the same as his own composition, warranted by the word, or under the hand of his Teacher; he ought to know, and to avoid the fifteen common faults; he ought also to know the usages necessary in holding a Chair and Eisteddvod, and to be skilled in the genealogies of the nobility, and in history.
A master Disciple ought to know the whole that the pupil Disciple ought to know, and therewith to sing like a disciple in all the chaired metres, to know the system of their quality and kinds, to avoid all the faults, to be skilled in history, as taught by the primitive Bards according to the privilege and usage of the Ancient Cymry, to trace the pedigrees of the innate princes and noblemen of the nation of the Cymry, to be acquainted with the history of all their laudable deeds and usages, to know the privileges of the nation of the Cymry, their substance and quality, to be able to record all these things before a Chair, to commit the whole methodically to book, to regulate and arrange a Chair and Eisteddvod, according to the judgment of a Bard, who is a chaired master of song, and to know the articles of the wisdom of the Ancient Cymry, and proper arrangement of the Cymric language, and all its syllables, words, and sentences, and to write them properly and systematically; he ought to know in memory and viva voce all the privileges and usages of the Bards of the Ancient Cymry, and their proper arrangement, and the memorial and knowledge respecting the ancient primitive Bards, their songs, and Books, and all the history which is derived from then.
And when, by means of his own singing, he shall exhibit all the chaired metres, according to their kinds founded upon primary quality, to be a masterly science of music, he is entitled to a Chair; and when he shall have obtained three, he will become a Chaired Teacher, and be entitled to the protection and privileges conferred upon Bards according to the privilege and usage of the Ancient Cymry. And before he obtains a Chair, he is deemed as the companion of a chief of song.
22. A Bard has three claims, and he is not entitled to his fee or degree, where he acts not according to them.
The first is, to maintain in a methodical song the memorial of the commendable deeds of princes, lords, wise men, innate proprietors, and every worthy servant of the nation of the Cymry, for their own praise, and in order to shew the present and future generations what is incumbent upon them in respect of usage, act, conduct, and aim in all that is praiseworthy, for the instruction, promotion, and maintenance of these things to the nation of the Cymry, and for the amusement which arises from the knowledge of them.
The second is, to uphold the Cymric language, and to teach it, as to its substance, quality, and arrangement, to such as may desire, to teach the proper writing of it, and to teach what in it refers to Bardism, vocal song, and their appurtenances.
The third is, to maintain the memorial of genealogies, and nuptial feasts, lest any proprietary and innate family of the nation of the Cymry should happen to suffer degeneracy. The man’s descent should be traced from the ninth generation, when it cannot be traced from a proprietary lineage, the derivation of which is known before memory, the same being a princely tribe or a baronial tribe. This is, lest the privilege and protection, which are due to no man whatsoever, except to a proprietary Cymro, or an innate Cymraes, should befall the degenerate, the alien, the foreigner, and the unprivileged villain. The woman’s descent should be traced on the father’s and mother’s side, as to posterity and origin, from innate Cymry, such being a privilege to her, being an innate Cymraes, which cannot be to a foreign woman, or to the daughter of an alien; for the latter does not possess the privilege of a proprietary Cymraes, though an alien or a foreign woman does not corrupt the lineage and descent of her husband and children.
For these reasons the genealogical descent of the nation of the Cymry ought to be traced, kept in memory, and preserved accurately, in order to distinguish between noble and mean descent, and in respect of native and foreigner, and of alien and baron. On this account, in right of his office, and the art of his song, a Bard is entitled to his fee by privilege and usage, and a penny from every plough; and where money cannot be obtained, he should make a seizure, and submit it to the judgment of twelve men of country. And because of this system, in every nuptial feast it is right and proper that the Bard should be under the privilege of a Chair and Gorsedd; and it appertains to the lord of the territory to make that arrangement, lest the five free acres should lack privilege. It was, in order that these particulars should be conducted rightly and duly, that the system of compiling the lineages of descent was first arranged.
42. The three primary offices of a Bard: to maintain peace and tranquillity; to maintain and improve good usages; and to maintain the memorial of goodness, sciences, and laudable deeds.
50. The three successful objects of a Bard and Bardism: to polish and civilize a nation; to render a country socially inhabitable; and to improve sciences.
132. Three things which a Bard ought to do: to learn minutely what he sees and hears; to keep closely what he learns; and to exhibit accurately what he knows.