The musical interval between two notes depends on the ratio of their frequencies. An octave is a ratio of 2:1 and, in equal temperament comprises 12 equal semitones, which therefore have a ratio of 21/12.
3 semitones down from G is an E :)
It is diatonic. Di means two, so you can think of it as two tones. A chromatic semitone would be from D to D#, or Eb to E. The difference is that Chromatic semitones use the same letter name twice, while diatonic semitones do not.
There are 7 semitones in a perfect 5th.
The semitones are found between the F# and G, and then between the C# and D.
Two
The musical interval between two notes depends on the ratio of their frequencies. An octave is a ratio of 2:1 and, in equal temperament comprises 12 equal semitones, which therefore have a ratio of 21/12.
3 semitones down from G is an E :)
It is diatonic. Di means two, so you can think of it as two tones. A chromatic semitone would be from D to D#, or Eb to E. The difference is that Chromatic semitones use the same letter name twice, while diatonic semitones do not.
The definition of concert pitch A has, since 1939, been standardized to 440 Hertz. The difference between any two consecutive pitches on a piano is equal to the twelfth root of 2. Since middle C is nine semitones below concert pitch A, rounded to two decimal places, this is approximately equal to 440 / ((2^(1/12))^9). Rounded to two decimal places, this is equal to 261.63 Hz.
There are 7 semitones in a perfect 5th.
The semitones are found between the F# and G, and then between the C# and D.
It is half a note in pitch
4
An augmented second is an interval comprising three semitones and two note names - for example, C to D sharp.
Chromatic
If you go to a piano and count down 2 semitones you land on a C. D double flat is a C just with another name. Double flat means you flatten (lower) the note by 2 two semitones.