What is a semitone?
The semitone is the smallest interval between sounds.
On a piano, it corresponds to two adjacent keys - it fits between the white and black keys, or in two cases between two white keys (those that are not separated by a black key).
The interval of C to C# is a semitone.
On the guitar, semitones are between two frets. A semitone corresponds to a minor second. And two minor seconds, or two semitones, form a whole tone.
The semitone is also the smallest interval between notes in MIDI. However, in digital pianos and MIDI controllers, like on the guitar, you can bend and lower sounds at much smaller intervals. A special pitch-bend wheel is used for this, which we wrote about here, or an ordinary expression pedal connected to the computer via this simple adapter.
Most modern Western musical instruments are tuned in the equal temperament system. Semitones are an important part of this system, because an octave is divided into twelve equal semitones. The chromatic range consists of all 12 semitones.
There are two types of semitones to know about:
- Chromatic semitones
- Diatonic semitones
What are chromatic semitones?
Chromatic semitones are when you have a semitone interval where both notes have the same letter name.
For example, C to C# and Gb to G are both chromatic semitones.
This is where we get a chromatic scale from. A chromatic scale has twelve notes in and each note is a semitone higher than the last.
What are diatonic semitones?
Diatonic semitones are when you have a semitone interval where the two notes are different letter names.
For example C to Db or F# to G.
Chromatic semitones and diatonic semitones are the same actual notes though.