As kids, many of us received home-made presents: a sweater or pair of socks, perhaps, or—if you were unlucky—a home-made crocheted bow tie you were forced to wear when Auntie came to visit.

On today's date in 1720, Johann Sebastian Bach started a home-made present for his 9-year old son, Wilhelm Friedemann. It was a collection of little keyboard pieces designed to help him learn to play the harpsichord.

These days, just about everyone who studies the piano at one time or another finds the music for the Two- and Three-Part Inventions of J.S. Bach propped up in front of them.

Here's how J.S. Bach himself described these pieces: "Straightforward Instruction, in which amateurs of the keyboard, and especially the eager ones, are shown a clear way not only of learning to play cleanly in two voices, but also, after further progress, of dealing correctly and satisfactorily with three… all the while acquiring a strong foretaste of composition."

In the case of little Wilhelm Friedemann, it did the trick. Not only did he master the keyboard, he became a composer himself.

Even just attentively listening to Papa Bach's inventions can have its rewards, according to the late music critic Michael Steinberg, who wrote, "Bach has done such a good job at inculcating 'a strong foretaste of composition' that… they will make the hearer a better, that is, a more aware and thus a more enjoying, listener as well."