Watch the Am: 6m - 4 - 5 in C online guitar lesson by Marcy Marxer from Ukulele for Guitar Players

6m, 4, 5 major - Key of C. The new chord here is Am. This progression is a natural minor progression since the 5 chord is major and not a 7th chord.

We live in the pop music domain with this and the following progressions in this section.