Chord TheoryLevel 4 — Roman Numerals
The I-IV-V Progression
Understand the three most important chords in any major key using Roman numerals.
Start Lesson in ChordColor →Instructions
- Set Level 4 on Guitar. Select C Major chord.
- Set the key to C Major (tap "Set Key" in the display settings).
- Look at the Roman numeral row — C is labeled "I" (the one chord).
- Click "IV" in the Roman numeral row to select F Major — the four chord.
- Click "V" to select G Major — the five chord. I-IV-V = C-F-G in the key of C.
- Open a song in Songs that uses I-IV-V (many folk and rock songs do).
TIP
The I-IV-V progression works in every key. In G major: I=G, IV=C, V=D. In D major: I=D, IV=G, V=A.