Basic Elements Unit #9: Diatonic Triads (aka "The Roman Numerals")
"Diatonic" triads are triads that belong to a certain key. (Harmonies that fall outside the key would be called "chromatic.") We refer
to them using roman numerals - the chord built on the the first scale degree is called "the I chord," that which is built on the second
degree is "the ii chord," and so on. We use this terminology to talk about harmonic progressions, and so before you
move forward it is important to know exactly which notes are in any diatonic triad in any key.
Here's a more detailed handout I've prepared on the subject.
And you could try your hand at these two worksheets:
The Major Diatonic Triads
The Minor Diatonic Triads
Here's an answer key for the first worksheet.
Extra Practice on the Web: emusictheory.com
As usual Robert Whelan has a nice quizzer on this that you can use in your (java-enabled) web browser. When you launch the
program, however, the initial settings may be too advanced for you - the only category you want to quiz (at first) is "diatonic triads."
Extra Practice for PC: My Theory Quizzer
And of course if you have a Windows PC you can try my rudiments quizzer. You type out your answers on
the keyboard, which can be a lot faster than a graphical interface, and the "torturematic quizzing algorithm" goes back repeatedly to questions you get wrong.