What is the name of a triad built from root, major third, and perfect fifth?

• A. Diminished Triad
• B. Augmented Triad
• C. Major Triad
• D. Minor Triad

Answer: (C)

A triad that has a root with a major third above it and a perfect fifth above it is called a major triad. This naming comes from the specific interval pattern: a major third (four semitones) from the root to the middle note, and a perfect fifth (seven semitones) from the root to the top note. For example, the C major triad is C–E–G, where C to E is a major third and C to G is a perfect fifth. If you changed the middle interval to a minor third or the top interval to anything other than a perfect fifth, you’d get a different triad (minor, diminished, or augmented), but the 4-semitone and 7-semitone pattern identifies a major triad.