Intervals from the Tonic
The distance between two notes is called an interval, normally counted in scale steps.
Whilst there are different types of intervals, you won’t need to recognise the different types of intervals, only the interval itself.
Intervals are calculated by working out the number of scale steps from the lowest note to the highest note.
In the image below we have a G, followed by a D.
The scale of G Major goes G-A-B-C-D. These means that D is the fifth note (you count the first note when calculating intervals) from G, making the interval a fifth.
The image below shows the interval of a third. As stated earlier, when calculating an interval, you use the lowest note at the starting point. Therefore, G-A-B is the third note of the major scale, so the interval below is a third.
In your exam it is important to pay attention to the clef. Below we can see that the lower note is C, due to the bass clef being used. E is the third note of the C major scale, so the interval is a third.
Below we have a C, followed by another C higher up. The distance here is eight scale steps (C-D-E-F-G-A-B-C), however we call this interval an octave. The octave is a term you will come across regularly, and it is essential you remember it for future grades.
Finally, below we also have a C, followed by the same C. The distance is one scale step, however instead we call it Unison. Unison’s are also a common term, and remember what a unison is will be very useful in the future.
Melodic and Harmonic Intervals
There are two different types of intervals, melodic and harmonic.
Below is the same interval displayed four different ways – the interval is a fourth (B♭ is the fourth scale step in F major scale).
If the two notes are played one after another, they are considered melodic, such as those on the left in the image below interval.
If the notes are played on top of each other, (and are therefore written on top of each other) they are harmonic, such as those in the right of the image below.
When a harmonic interval is that of a second, the notes would overlap if written on top of each other. Instead, we write them like this:
In the exam, you will be expected to be able to identify the intervals of notes that start on C, G, F and D. So make sure you know these scales well.
For now, this likely seems very similar to scale degrees, however in the later grades when we explore different types of intervals the differences will quickly become apparent.