Major sounds bright and settled, minor sounds dark or sad. The difference is one note: the 3rd. G major has B; G minor lowers it to B♭. That's all it takes to change the mood.
Play G then Em, C then Am, D then Dm, and listen for the change. Then try it with your eyes closed while someone else plays.
Try this
Play E then Em, A then Am, D then Dm. Say "bright" or "dark" before each chord rings out, then check.
My notes
Saved in this browser only.
How well do I know it?
How do I like it?
Keep it close
🤷
Note