Legato - Three Note Pattern 1
To get you started on the right track with legato, this exercise is meant to not only cover a common three note pattern, but to also get your fingers used to the stretching and endurance that is needed to master legato. The exercise will serve as a good foundation to build advanced legato technique.
Nothing fancy here - the fretboard diagram simply shows the three note pattern you will be playing in this exercise. You should visualize where this pattern exists elsewhere on the fretboard. Not only will that build your fretboard knowledge, but it will also help you visualize a "starting point" for any scale that starts with these notes.
This legato exercise mirrors somewhat my alternate picking exercise Alternate Picking - 3 Notes Pattern 3. But this is a good thing, because repetition and variety on the guitar is a great way to get concepts into long term memory.
The exercise is fairly self explanatory, so let's not waste any time and get right to playing the exercise!
You see in the tablature that there is an Ex. A and an Ex. B. In Ex. A I indicate fingerings that would be most common for playing this sort of line. In Ex. B, I vary the exercise a bit and also indicate an alternate fingering which will be more challenging for you to play because of the stretching it requires. But persevere - if you are not used to stretching your fingers in this way, after mastering the exercise your fingers will have a new sense of freedom, which will allow you to play more intricate legato lines.
Criteria for Mastery: You can cleanly and smoothly play Ex. A and Ex. B at 150 BPM or faster
When considering just the Major Scale and its modes, there are only three scales that start out with the three notes used in this exercise. It might seem hard to believe, but it is true. The only scales that start with A, B, C# are those scales starting on A that have a major type of sound. What do I mean by a major sound? Well, play an A, B, and a C#. From A to C# is a Major Third Interval, and between A and B and between B and C# is a Major Second interval.
The nature of the intervals in this pattern is what gives the major quality. If you looked at my guitar lesson Triad Arpeggios - 2 Strings, where I talk a bit about the theory of triads, you might recall that for a given major scale and its modes, there are only 3 modes that have a major quality: Ionian (e.g. the Major Scale itself), Lydian, and Mixolydian.
This means that the only scales starting with the notes A, B, C# are A Major, A Lydian, and A Mixolydian. I believe it is useful to recognize this about three note patterns, because it helps you build phrases with a characteristic major sound - useful for setting the mood of a piece - and it also helps you see where on the fretboard you could launch into a Major, Lydian, or Mixolydian scale. In that sense, seeing three note patterns in this way acts like guideposts for your fretboard navigation.