Well, intervals refer to the distance between two notes. Triads are built from three notes.
If I have a major scale, I spell it with numbers like this;
1 2 3 4 5 6 7
And we build chords and triads from this. If I wanted to create a power chord out of this scale, I would just use 1 and 5, so this interval is called a perfect fifth. I could also have 1 and 7, which would be a major seventh, or 1 and 3, a major third.
If I have 1, 3 and 5, I have a major triad. If I have 1, b3 and 5, I have a minor triad. Getting the idea? Cool.
I would get a book and brush up on your scales and stuff, then this will come to ya real easy.
And God said, 'Let there be rock!'
-And it was good
-And it was good
