Nice and catchy title to the video, but it says what it is.
Why struggle with stretches? Even common chords can present difficulties in the first position: the usual culprit reluctant to stretch is the third finger. If you use a capo on the 5th or 7th fret, the frets are narrower and the arm is closer to the body making access so much easier. Over the months the capo can be placed on the 4th, then the 3rd etc., the small differences in stretches become achievable.
But, as usual, pin-point accuracy of fingertip placement is important - the closer the tip is to the fretwire, the less pressure needed to sound a note clearly.
The video also looks at the other benefits of using a capo, for example, the guitar sounds 'crisper', the shorter string length adding to the notes' clarity.
Regarding chordal playing, the video fails to mention that at times, instead of playing a lot of nightmare bar chords all over the fingerboard, it makes much more sense to put a capo on and play in the first position using chords with open strings. I was brought up to think this was cheating, but those chords sound good on the guitar and due to their close proximity to each other will help playing sound smooth and that is our ultimate aim after all.
Did I say picking out the melody was the most difficult thing to do well on the guitar? I lied, legato is! Playing legato is the essence of beautiful music and our target must be to replicate the voice soaring seamlessly between notes - no silences. To achieve this on the guitar is a nightmare.
This exercise is laughable in its simplicity, but a pig to play well. Even played slowly, the first finger of the left hand has to leap swiftly onto the next string, synchronising the pluck of the right hand finger with no discernable silence; this is once the right hand can play legato effortlessly though.
When we play the guitar, we should always conserve energy and aim to release tension to increase musicality and to minimise fatigue - sadly this approach is neglected by many players and teachers alike.
Much emphasis is given to the use of the fingers of the right hand, but we mustn't neglect what's going on with the thumb. Using the thumb is a prime example of where we make a huge effort to create a sound when we needn't.
This video explains the ideal approach to using the thumb, but as usual, for a relaxed stroke to become second nature, a huge amount of effort and time is required, but well worth the dedication.
This is a fantastic piece to help develop contrasting dynamics and thankfully is very beautiful to listen to and play - it makes a difference to develop on pieces that we love. I love Leo Brouwer's music, particularly from his more romantic period but even his modernist pieces: I grew up on 'Estudios Sencillos' which were like a breath of fresh air to a young player only aware of Giuliani, Sor and Carcassi and have grown to love their quirky harmonies, but their importance for students of the guitar lies in the development of good technique.