In fact, I can't really capture the difference between major and minor chords, even if they are in the same key. Here's what I did. I did a recording for ear practices. I had a power dyad playing in the background while I record myself playing major and minor 3rds. After like an hour or so, I'll start hearing them over to identify them if they are majors or minors. The sad news is, I can't - Most of them are wrong. Then I tried them over with my guitar again. This time, much better, but I'm getting only 60% of it right.
I was told to be slightly tone deaf too. So.. yea, I want to get myself out of this predicament. To be able to really hear the key of musical pieces, if there are key changes or not. I want to be "real buddies" with these keys just so I know "who" am I playing with.