Rock in E minor (basic version) — alternating bass fingerstyle
This grid (Em, C, G, D) follows exactly the same degree pattern as another grid in the catalogue in A minor (i-VI-III-VII): it's the same harmonic loop, simply transposed. Recognising that kinship isn't just a theory exercise: the alternating bass pattern you're working on here carries over unchanged to any i-VI-III-VII grid, whatever the starting key.
Tips
If you already know the equivalent grid in A minor from the catalogue, play both back to back to hear that it's the same loop.
Work the thumb alternation on a single held chord before applying it to all four.
Once this pattern is automatic here, try transposing it mentally to another minor key: that's the real test of understanding the shape.
Chord progression — Em
Bar 1
Em
i
Bar 2
C
VI
Bar 3
G
III
Bar 4
D
VII