A Major 7th is considered a strong dissonance because of it’s rough sound.
The inversion of a Major 7th is a Minor 2d. When played as chords, these two sound very similar.
If you struggle hearing the difference with these, or any other intervals, consider taking a Custom Lesson.
To do this, click the “Custom Lesson” link at the top of the Exercises page.
|Major 7th   ||
|Minor 2nd   ||