Tonic triads

About 2 min to read, then 5 practice questions

Three notes in 3rds

A triad is a chord of three notes, stacked one above another a 3rd apart. On the stave that looks like three lines in a row, or three spaces in a row.

The tonic triad is built on the tonic, the first note of the scale. It uses the 1st, 3rd and 5th degrees of the scale, with the tonic at the bottom.

The tonic triad of C major: C, E and G, three lines in a row

The four Grade 1 tonic triads

Key	Tonic triad
C major	C E G
G major	G B D
D major	D F sharp A
F major	F A C

The tonic triad of D major: the key signature makes the F an F sharp

The same triad with no key signature: the F sharp needs its own sign

Tip: when there is no key signature, check each note against the key: D major's tonic triad always needs F sharp.

Worked example: the missing note

Two notes of the tonic triad of G major are written: G and D. What is missing?

The tonic is G (the bottom note).
The 3rd above G is B (G, A, B).
So the missing middle note is B, on the line between G and D in the treble clef.

The tonic triad of G major in the bass clef: G, B and D, three lines in a row

Practise this: 5 questions, about 4 min

Answering from memory soon after reading is what makes it stick, so now is a good time.

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