While it is obviously important to learn where the notes are on the fingerboard, it can be equally useful, to learn how the various intervals look and feel on the mandolin fretboard. In fact knowing some of these shapes can make the task of learning which notes are where much easier.
We'll look at the two intervals we've already met and add a third one to our repertoire. Incidentally, although the previous section related everything to the pitch-class ‘C’, there is nothing intrinsically special about this, or any other pitch-class. We had to start somewhere and, tradtionally, that place is middle C.
The simpler of our two shapes in the semitone. Usually, a semitone consists of two notes on the same string separated by a single fret (for our purposes, the ‘nut’ of the mandolin is considered to be our ‘zeroeth’ fret):
There is, however a less common shape involving two strings. To understand this, we must consider the Seventh Fret Rule. Understanding this is essential to unfolding the mysteries of the fretboard. The rule states that, on strings 2, 3 and 4
We can also express the Seventh Fret Rule as: moving up a string
Just as there are two semitone shapes, there are also two octave shapes.
The octave shapes can help with fretboard familiarisation. For example, if we know that the open fourth string is a G, we can deduce that string-3/fret-5 is also a G. From here we can further deduce that string-1/fret-3 is a G.
The next interval we'll add to our arsenal is the tone. Predictably, one tone is equivalent to two semitones. Like the semitone and the octave, we'll consider two tone shapes. The more straightforward shape involves two notes on a single string with two frets between them...
By applying the Seventh Fret Rule, we can derive our second tone shape similarly to how we got our second semitone shape.
Although we can have this shape on the 6th and 1st frets, this is sufficiently rare and awkward to play to allow us to ignore it (at least for now).
Next: Major scales