Question: I’ve often read that to play the piano properly, you must be proficient in key identification (knowing what the key is, based on the number of sharps or flats it has). As long as I play the music as written, why is it necessary for me to know what key it’s in? I’ve tried memorizing all the major and minor keys, but can only remember the easy ones (C, F, A, Bb, etc.).

So I thought about what the advantage of memorizing them would be, and couldn’t come up with anything. Maybe if I played in a band or a group with other instruments, I would have to know the keys, but most of us piano students just play for our own enjoyment. So do I really need to know what key I’m playing in? Thanks.

– Willard Crawford (Llano, California, USA)

Albert’s reply: Yes! Knowing all the keys is a direct consequence of knowing your scales, as well as the key signatures. Once you know them well, learning music becomes a far easier, not to mention more enjoyable, task, for several reasons. First, you’ll immediately be able to recognize and understand the structure of music much more easily. This alone will increase your learning speed, as well as your retention rate.

Second, once you know all your scales (and with them the keys), your fingers will automatically gravitate towards the right keys on the piano when you’re playing in a given key. The knowledge of the scale degrees will be so ingrained that playing in that key will be like tying your shoes. The notes of the scale and the piano keys you press will become as familiar to you as your own name. Your memory will be greatly solidified and you will be vastly more confident as a performer as a result.

It’s actually very easy to remember the keys with a simple formula. Remember that a sharp raises a note, while a flat lowers a note. Thus, think in terms of going up (sharps) or down (flats).

Let’s start with the sharp keys. Start on C major, which has zero sharps or flats. Each key is a perfect fifth above the previous one. A perfect fifth happens to be the interval between the first note of the scale (the tonic) and the fifth note (the dominant). The fifth note of the C major scale is G (C D E F G), so the key a fifth above C major is G major. G major has one sharp (F-sharp).

The fifth note of G major is D (G A B C D), so the next key is D major with two sharps (F-sharp and C-sharp).

The fifth note of D major is A (D E F-sharp G A), so the next key, with three sharps (F-sharp, C-sharp, G-sharp) is A major.

And so on for the sharp keys.

For the flats, again start on C major, with zero sharps or flats. A perfect fifth down from C is F, so the key with one flat (which happens to be B-flat) is F major.

A perfect fifth down from F is B-flat, so the key with two flats (B-flat and E-flat) is B-flat major.

And so on for the flat keys.

All of this is displayed graphically in the circle of fifths, which will make it much easier for you to learn all the keys.

For a very easy way to learn the order of the sharps and flats, please see the article titled Memorizing the Keys!