The world wasn't always all Korg Synthesizers and electric guitars - in fact, up until the 20th Century, you could say that everything was essentially acoustic.
But that's not going back far enough for the purposes of this article - we want to find the oldest musical instrument of all time, or at least find the oldest instrument that's still around and played today.
Heck, why not both?
Finding the oldest instrument ever also plays on our definition of musical instruments in the first place. After all, producing a couple of sounds by banging a stick on a rock could arguably be the world's first drum. That's why we'll want to define an instrument as something that was created specifically in order to make music - and was more than a stick.
With this definition, we see that a pre-historic flute was actually one of the oldest instruments we've ever seen, discovered to be from a time some 35,000 years ago. And you thought Bach was old.
(By the way, if you want to argue that a flute is "just a stick" I, well, I can't really argue with that.)
Finding a "flute" satisfies both of the questions posed in the first paragraph, so let's move forward in time tens of thousands of years and find out what instruments of today look like they did hundreds of years ago.
We know the piano was a favorite of Mozart and Beethoven and that the organ and harpiscord were utilized by Bach. But we do know that instruments like today's harps and even guitars have been around for thousands of years. King David played the lyre in the Old Testament of the Bible, which suggests that music has been popular for these same millenia.
With that in mind, it's not difficult to tell which instruments have been around the longest. Flutes can be simple and sometimes easy to make; it's not a big surprise that prehistoric man figured them out.
Plucking a string is about as old as music itself, which is why it's not surprising to find that harps and lyres were played thousands of years ago. But the musical explosion of the 18th Century on has seen a dramatic increase in the sophistication and usage of a wide variety of instruments.
Today, there are endless amounts of sounds we can create on the computer.
Including a prehistoric flute.