What was the game-world identity of Bard's before? If a Magus is a Wizard/Fighter in PF, is a bard a Wizard/Thief with musical flavor and subbing out back-stab for knowledge skills?
What literature are they patterned after? Was it the Finnish section of de Camp and Pratt? What distinguishes them from a Wizard that uses words (like Earthsea or Name of the Wind) except for singing instead of saying?
Should they be more like Warlocks but with songs? Is that too limiting?
The D&D bard, to the best of my knowledge, is based on the following:
The Celtic Bard, as a musician/performer and master of lore, the 2e PHB specifically cited Amergin Glúingel from Irish folklore as an inspiration for the Bard class.
The 2e AD&D PHB also cited Alan-a-Dale and Will Scarlett of the Robin Hood myths as examples of Bards from folklore.
The Scandinavian Skald, as a similar archetype of a loremaster and performer to the Celtic Bard is often cited as an inspiration for the class.
It seems to be the D&D interpretation of the archetype of the minstrel, the jongleur, the bard, the skald. . .the performer and master of lore that may serve in a court or may wander from place to place, but they are adept at the performing arts and often possessed of great learning and knowledge.
30 years of D&D since 1e has made the class a little self-referential, like how the modern D&D Ranger is as influenced by the Drizzt Do'urden novels as by any historic, literary or mythical roots, as the bard now combines the original source of the class being master of lore and performing arts with a general "jack of all trades" class that has at least basic elements of most other classes, such as the basics of swordsmanship from a fighter, the basics of thievery from rogues, rudimentary healing magic from Clerics, and basic use of other magic from Wizards.
