Have you ever heard someone mention the notes C5 or A2 and had no idea what it means? It’s actually from the American system for notating pitches, called Scientific Pitch Notation (SPN). This sounds really complicated, but it’s actually really simple! All it takes is a basic understanding of numbers and the letters A through G, and seeing how those numbers are used on a piano keyboard. Here’s your easy guide to Scientific Pitch Notation.
A through G: The Basics of the Piano Keyboard
On a piano keyboard, there are 88 keys. We’re going to look at the white keys only for understanding the basics of SPN. The very lowest white key at the bottom of the keyboard is called an A. The next white key — the one just higher than it — is called a B. The next one is called a C, the next one’s a D, then an E, then an F, and finally a G. THEN the whole thing starts back over with A, and you keep on going up the keyboard. As you go up the keyboard pressing A-B-C-D-E-F-G, A-B-C-D-E-F-G, you’ll start to notice a pattern: all the As sound like the same note; they’re just higher or lower than each other. The same goes for all the Bs, all the Cs, and so on.
Octaves and SPN
Since these note names are repeated over and over, each series of notes or each set of keys from A to the next A is called one octave. All the notes from B to the next B, or from C to C, or from D to D, etc. are also called an octave. Here is where SPN comes in. Due primarily to the major scale in music theory, we don’t actually start naming these octaves until we hit the very first C on the piano. But for now, don’t worry about why SPN is measured that way — just know that when you’re looking at the low end of the keyboard, the 1st octave starts with the very lowest C key. Since it’s the 1st octave, this key is called C1, and the next key D1, then E1, then F1, G1, A1, and B1. Then, once you reach the next C, you’ve reached the 2nd octave, and the keys are called C2, D2, E2, F2, etc. (The two lowest keys on the piano, the A and B below C1, are called A0 and B0 in Scientific Pitch Notation.)
Yep, it’s that straightforward! So the next time you hear someone mention the note C5, you’ll know it’s the C in the 5th octave on the piano keyboard. You’ll also be able to find that pitch by looking at a piano keyboard and counting up from C1. Scientific Pitch Notation is used in singing and across many different instruments, not just the piano, so it’s good to have a basic understanding of it when you’re learning music.
Fun fact: C4, more commonly called Middle C, is one of the most important keys on the piano and is typically the first one beginning pianists learn to recognize in sheet music. Learn more about music theory.