- Note
- A single pitch. In your piano roll it's one horizontal block - C4, D#3, whatever.
- Pitch
- How high or low a note sounds. Doubling frequency = one octave up.
- Octave
- 12 semitones. Move a note up one octave and it's the same letter, twice the frequency.Example: C3 → C4
- Semitone (Half step)
- Smallest step in Western music. One key on the piano to the very next one, black or white.
- Enharmonic
- Same key, different spelling. C# and Db sound identical.
- Interval
- The distance between two notes measured in semitones - minor 3rd, perfect 5th, etc.