Most of my comments on the term 'bard' are based on the origins of the term as the Welsh Bard or Scottish/Irish Fili. Merlin was actually the archetype for a bard and was based on the Myrridin the bard. The word druid refers to bards and wizards too. Vainamoinen was a bard because the magic he used was with the power of his voice and he sang his magic, and used a kantele. He was associated with music and poetry. An example was when he sang a boat into creation and sailed it across the sea. In Finnish stories spells were created from lyrics and that's where that magic came from. That's a bard, easily, based on the mechanics used. Any class defined by the mechanics as a bard in game terms could still have a priest background (like DDN has) or be religious on top of the class structure.
Vainamoinen is even referred to as "the eternal bard".
Gandalf was patterned after stories of Merlin and Vainamoinen as a lorekeeper, and when he used magic he chanted (as bards cast - it's not all lutes and dancing) with power in his voice. That's a bard too. The issue is a lot of people don't understand or know the origins of bards. The role was to maintain history using a oral tradition, the term bard is refers to prophet in an older meaning, and bards were judges, historians, teachers, arbitrators, mediators, advisors, herbalists, and healers among other things. The role changed over time as oral tradition made way to written history.
The reason bards are not priest is because they didn't necessarily serve in religious orders or functions. I know clerics are fabrication based in part on teutonic knights, hospitalers, and templars and giving divine magic. Priests as a class also prayed for magic. Bards were born with the gift of magic. It was called 'awen' and meant inspiration, but not in the modern sense; inspiration was "in a state of spirit" and true inspiration carried a more supernatural meaning as it stemmed from the root word "spirit".
D&D separated the healing and buffing divine magic from arcane magic as a rule and in the process created room for bards because they shared commonality as historians, knowledgeable, and magicians with the arcane classes; and healing magic like the divine classes. The song magic separate from the spells is a D&D mechanic because what bards in stories did was use lyric verse and poetry to create magic in the power of their voice. This is like Amergin (a bard) calming the storms sent by the druids with his poetry during the Milesian invasion when the invasion was predicated on his prophesy of victory and the reason the invasion began, or Taliesin (a bard) shaking the keep in which Elphin was imprisoned by singing up a terrible wind strong enough to shake the keep until Elphin was brought forth and Elphin's shackles dropped from him with another song when Taliesin and seen the imprisonment from home, or the example of Vainamoinen singing up a boat. Separating the classes by that song mechanic also provided distinction and could be reinforced by Ceasar's accounts of the bards inspiring the barbarians in battle during the Roman invasion.
Witches would also chant or sing in stories and follow the bard concept of making magic with singing or lyrics or verse. That's a definitive association and mechanic
There's a lot of a myth from which to draw the bard archetype. WotC is drawing more from the minstrel or jongleur approach that occured much later with bards. They kept the bardic knowledge, and provided bards expertise bonuses to skills so it's easy for a bard to be the most sagely and knowledgeable class in DDN by choice in those options but also not necessarily for those who want more of that rogues scoundrel wandering bard. It's handled by the skill choice and background because bards are also the only class in the playtest with an unlimited class choice from which to select their skills. Rogues get one more skill proficiency but from a specific list, a bards get the jack-of-all-trades bonus to non-proficient skills. I can take the guild thief background on a bard and choose some skills to go with it, and take expertise in my thief tool proficiency if I want to build a roguish bard. Background and skills help define the characters and I like the fact that the choice exists between taking a bard with a thief background or taking a rogue with a minstrel background, or taking a cleric with a minstrel background or taking a bard with a priest background, for example.
You are correct, a rogue can easily take proficiencies in bard skills with the right back ground and cover the skills. Not the jack of all trades or minimum roll on all knowledge checks but pretty good as the other skill based class. The rogue won't be healing anyone though, or casting spells as swift actions using the battle magic bard ability. The game could function just fine with the 4 classic classes but the 6 optional classes open up options. The bard could also be using silence, invisibility, and knock spells.
The college of wit is interesting, because it add more performance abilities but it's clearly based on the jester role based on the abilities and description with the magic applied per bard. The bard class itself is clearly less of the original bard caste and myths, and more of a middle ages jongleur or minstrel. It takes more of the modern definition of a bard as a poet and calls out the performance as magical, like a mix of the original bard stories and the wandering minstrel concept. There is more modern fiction using the same concepts even if it's not accurate to the original concepts and stories.
I agree, it doesn't cover the expected historical and literary archetypes. I can list off a lot of similar roles in a lot of societies if a person really wants. I can see the amalgam of old concepts and more middle ages concepts in there as DDN uses the name while making their own version of it. What I can do is build on it with the backgrounds and in the skill choices. I also expect more than 2 colleges when all is said and done. College of valor is clearly a 4E style meets 1E concept as what Mearls listed as the Celtic / Skald warrior concept. I agree they are on the high side of squishy on the scale for that but DEX based using bows and finesse weapons helps there. As I mentioned, college of wit is the traditional jester role. I'm hoping for a college of lore, college of medicine, and maybe a college of espionage for additional directions.
If I repeat myself or seem tired you are correct in that I am.
