Note that he's only searching songs written in C Major. A D Major would be outside the key so naturally it would be quite rare. The results are exactly as I w

Note that he's only searching songs written in C Major. A D Major would be outside the key so naturally it would be quite rare. The results are exactly as I would expect. F is the most common chord to follow E, because that's the primary way to resolve the dissonance of that note in C major. When E appears in other chords in C Major it will also tend to resolve to F unless there's a good reason not to (cadential 6-4). A minor is the next most common after F, because that's the next step in a descending circle of 5ths pattern (E, A, D, G, C)