Two semitones = a tone
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 semitones are found between the F# and G, and then between the C# and D.
There are 7 semitones in a perfect 5th.
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.
In a harmonic interval, two notes are played simultaneously. The arrangement is defined by the distance between the two notes, measured in steps or semitones. Common harmonic intervals include the octave (8 semitones), fifth (7 semitones), and fourth (5 semitones). The specific quality of the interval, such as major, minor, perfect, augmented, or diminished, further characterizes the relationship between the notes.
3 semitones down from G is an E :)
There are four semitones in a major 3rd interval.
There are four semitones in the interval between C and 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 semitones are found between the F# and G, and then between the C# and D.
There are 7 semitones in a perfect 5th.
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.
To change key, you typically need to change by either 5 or 7 semitones.
It is half a note in pitch