Now you know all 12 notes. The next step is measuring the distance between two notes using semitones and tones. These measurements let you describe intervals, build scales, and transpose a part without relying on a particular key.
The semitone - the smallest step
A semitone (also called a "half step") is the smallest distance between two notes. On a piano, it's the very next key - whether that's white to black or white to white.
C to C# - one semitone apart
The tone - two semitones
A tone (also called a "whole step") equals two semitones. Skip one key and land on the next. The important part is the count: a tone is two adjacent key-to-key steps.
Watch out for E-F and B-C. They are tones apart in letter order, but there is no black key between them, so each pair is only one semitone apart.
C to D - one tone apart (C# is skipped)
Counting semitones
Semitones are the universal ruler of music. Any distance between two notes can be described as a number of semitones. This is how scales, chords, and intervals are defined.
Common distances from C
Don't worry about memorising interval names yet - they come up again in the chords and progressions topic. Just notice how the number of semitones defines each distance.
Walking up in semitones
If you play every single key from C up to the next C, you walk through all 12 semitones. This is called the chromatic scale - it includes every pitch class in the octave without skipping a semitone.
The chromatic scale - every semitone from C4 to C5
Most music doesn't use all 12 notes at once. Scales pick a subset - usually 7 - by choosing specific semitone and tone steps. That's exactly what the major scale pattern does (tone, tone, semitone, tone, tone, tone, semitone).
Try it
Choose C as your starting note. Predict the destination before tapping each pair: one semitone, one tone, a major third, and an octave. Use the piano to check your prediction, then repeat the exercise from F.
Count the keys you move through, not the keys you land on. A tone is two semitones, so it skips one key in between.
Why steps matter for production
When you choose a key and scale in a tool like Starts, you're really choosing a pattern of semitone and tone steps. Understanding these steps means understanding why certain notes sound good together and others clash.
Key takeaway
A semitone is the smallest step (one key). A tone is two semitones (skip one key). All distances in music boil down to counting semitones. The chromatic scale uses all 12. Most scales select 7 with a specific pattern of tones and semitones.
Next: how computers represent all of this with a simple numbering system - MIDI notes.
See step patterns in scales
Pick different scales in Starts and notice how the tone/semitone pattern changes.