Grade One Music Theory - Lesson 14: Tonic Triads
What does the term "tonic triad" mean? We've already learnt that the tonic is the first (and last) note in a scale. "Triad" means "chord built with thirds".
A "tonic triad" is a music theory term for a chord of three notes and the lowest of these notes is the tonic of the key we are in.
Here's a tonic triad in G major:
Building Tonic Triads
Tonic triads are simple to build. You don't need to build them yourself in Grade One music theory, but it's pretty easy so we'll show you how anyway!
First you need to know what key you are in. Remember that for Grade One music theory, you only need to know the keys of C major, G major, D major and F major.
Let's build a D major tonic triad.
The tonic is the first note of the scale. We are in D major, so D is the tonic. That's the first note we need to write down. It's going to be the lowest note of the chord, so we'll write a low D, so that we have room to add notes above it:
The next note in the triad is the third note of the scale. The third note in the scale is F sharp, so we'll add that one now:
The last note of the chord is the fifth note of the scale, which for our triad is A:
Here is our finished tonic triad in the key of D major!
Tonic triads are always made up of the tonic, third and fifth notes of the scale.
We say that tonic triads are built out of thirds, because the interval between the lowest note and the middle note is a third, and the interval between the middle note and the highest note is also a third.
Naming the Key of Tonic Triads
In Grade One Music Theory, you might be asked to name the key of some tonic triads. This is very easy to do if you remember that the lowest note in the chord will give you the answer.
If the lowest note is C, then the key will be C major. You only need to know about major keys for Grade One Music Theory, so you won't have to identify any minor keys (in any part of the exam). So, you have four possible answers: C major, D major, G major or F major.
Make sure you pay attention to the clef.
Here's an example question. (Hover your mouse over the image to reveal the answer).
Name the key of this tonic triad:
Adding Clefs and Key Signatures
In the Grade One music theory exam, you might be asked to add a clef and key signature to some tonic triads. You will be told the key of the triads. Here's an example:
Add the correct clef and key signature to this tonic triad.
Look at the lowest note of the triad, and think about what that note would be with a treble clef, and with a bass clef. In our example, if we had a treble clef, the lowest note would be E. If we had a bass clef, it would be G. We need a G, so it must be bass clef.
Here's the clef added. Make sure you draw your clefs carefully. Look at Lesson 19 - Handwriting Music for more on drawing clefs.
Next we need to add the correct key signature for G major in the bass clef:
Look at Lesson 12 - Key Signatures if you need help on how to write key signatures.