Look, the game is born of swords and sorcery.
Swords ---> Fighting Man/Warrior guy
Sorcery ---> Magic-user/Wizard guy
Your Barbarians, your Knights in shining armor, mercenary Swords-for-hire, soldiers, warlords [small "w!" Everybody relax.], etc. etc... "Warriors," all.
Your Wizards, your "sorcerers/magic is an interior thing," your good and wicked witches, illusionists, enchanters, conjurers, necromancers, etc. etc... "Wizards," all.
Behind and/or alongside them are the "next tier," if you will, of archetypes: "The Support Classes."
Thief ---> Support through Skills/"Rogue" guy.
Cleric ---> Support through various combinations of all of the above/"gish" [but I hate that term so let's call it] "Priest" guy.
Your straight up thieves, pickpockets, burglars, your assassins/ninjas, scouts, spies, tricky tricksters, acrobats, pirates/buccaneers, etc. etc... Your skill-based help you out with non-combat heavy and non-magic-heavy stuff in non-combat/magic heavy ways, support class "Rogues," all.
Your clerics -from pacifist healer to militant crusader, undead hunter to wise counsellor and everything in between, your druids, monks/spiritual martial artists, I would argue your warlocks, one could conceivably throw paladins and rangers in here as well, etc. etc... Your combinations of magic and fighting ability, fighting and skills, magic and skills, fighting-magic-and-skills, in varying amounts in just about any conceivable flavor, support class "Priests," all.
The Bard, quite obviously, falls into the last of these possible archetypal categories, a support class that combines magic and fighting and skillsets (traditionally in D&D, as well as historically, including some level of skill in music, oration, knowledge/history and memory retention) in a wide variety of possible amounts -more magicky, more fightery, more skillsy, jack-of-all-master-of-none, et al.- as suits your Player Character concept. How you choose to imagine a particular combination with a particular flavor -historic, literary, or fantastic- is entirely up to you.
So, no. There is nothing "silly" about the Bard concept.