The chord progression in question is A major| F#minor| E major | D Major| which is essentially Purple Rain in A major.
Why is this called the Cornish pasty practice? Because I combine learning repertoire with technical exercises and theory. The cornish pasty is the combination of a number of meals all in one manageable package. So is this.
Exercise 1 : Learn the chords in all 5 CAGED positions. Be able to play them Vertically, Horizontally and in block positions. This exercise needs to be played evenly, cleanly, and in time, Ascending and Descending. Get really good at playing chords. No excuses.
Exercise 2 : This progression is in the Key of A. Take the A major scale in all 5 CAGED positions and practice playing it ascending and descending. Although ascending and descending scales are quite ” dry” remember to use vibrato and feel to make it sound musical at all times.
Section 2 : Play the scale using sequences. Play the scale using intervals. and variations in rhythmic groupings. 1/4 notes, 1/8 notes, triplets, 1/16th notes mix them up and remember to alternate pick and legato as required.
Exercise 3 : Arpeggios. Initially use Major and Minor arpeggios relative to the chords. i.e A maj| F#min |E maj | D maj || 5 shapes. 5 positions and then as the chords in exercise 1. remember rhythmic patterns as per scale exercise.
Exercise 4 : Pentatonic exercise. A major contains 3 minor pentatonic scales. Bmin C# min and F#min. Practice playing these, again using all 5 shapes, ascending, descending, in position. Working on phrases and licks. Remember every exercise needs to be as musical as you can manage.
Exercise 5 : This is an advanced practice concept so if it makes no sense at present don’t worry about it. Superimposed arpeggio ideas. Example A maj chord with C#min7 or E7 in it’s place. This will allow you to work through all the 4 note arpeggios available in the Key. Again these are played in as musical phrasing as possible and get used to joining them together to reharmonise and extend the harmony of each chord as the progression plays. This will take some doing but will be very rewarding.