Foundations
Twelve notes, then it repeats — forever. See exactly where they sit on the piano and the guitar, and the two spots where the pattern quietly breaks.
Music only has 12 note names before they start repeating. Written out, one half step at a time, they look like this:
Every step from one note to the very next one — no skipping — is called a half step. Walk through them below and watch (and hear) it happen on a real keyboard and a real string.
Low E string · fret 0 is open E. Every fret to the right is one more half step.
Notice: on the guitar string, every single fret over is a half step — always, no exceptions. On the piano, most half steps involve a black key... but not quite all of them.
See the pattern
Black keys never stand alone — they cluster in groups of two and groups of three, with a gap on either side. E and B are the white keys sitting right where one cluster ends and the next hasn't started yet. That gap is empty — no black key lives there.
The why
A black key is a "sharp" — the note exactly one half step above a white key. E# would be one half step above E... which is just F. B# would be one half step above B... which is just C. There's no room for a black key when the sharp would land on a note that already has a name.
Click the four notes that make up the two half-step pairs with no black key between them.
Tap a key to begin.
Cheat sheet
🧠 Black keys travel in pairs and trios, never alone — E→F and B→C are the two gaps with nothing between them.
Next step
Now that you know where the half steps hide, see how they combine into every interval.