Watch the Am to F Chord Connection online guitar lesson by Brad Carlton from Guitar Lab: Vertical Soloing

Measures 3 and 4 of our progression are Am to F (vi IV). This is different from the previous chord connections F to G and G to Am. Our previous chord links were adjacent diatonic triads whereas the Am to F change in bars 3 and 4 are a third apart (every other diatonic triad). What this means is there are common tones. The Am is spelled A (1) C (b3) E (5) and the F is spelled F (1) A (3) C (5). Notice how we have the A and C notes as common tones. There is a rule being applied here: any two diatonic triads a third apart will share two common tones. Since the A and C notes are common, try sustaining each of them over the chord change. Then use the remaining E to F move to lock up with the progression. The most important goal is to "pre-hear" these melodic moves that exist between the arpeggios. Always listen as you play to how the note you're playing functions against the prevailing chord. I'll also discuss the common tones between the A minor and F major pentatonic scales.