It is easiest to start with a C triad, which is major, and change it to minor, by lowering the middle note of the triad, from E to E  .

 

 

 

 

 

 

 

 

 

 

 

 

The sound of a major chord is cheerful, lowering the third makes a mournful sound, which let's you know it is minor.

 

The D triad is minor.  To change it to major, raise the middle note, from F to F  .

 

 

 

 

 

 

 

 

 

Every note is the root of a major and minor chord.  As you play each triad, listen to the sound and see if you can tell if it is major or minor.  If you believe it is major, lower the third to make it minor.  If you believe it is minor, raise the third to make it major. Your ears will tell you if you got it right.

 

 

 

 

 

 

(The B triad is tricky because both the 3rd and the 5th will need to be sharped to make the major chord; and in order to make it minor, lower the D   to D  .)

 

Triads can be built on black notes too.  For the C   Major chord below, the 1st, the 3rd, and the 5th are all sharps.  The 3rd is an E  , which is an F.  Try changing C   major into a minor.  Think of it as a sandwich cookie, such as: chocolate, vanilla, chocolate.

 

 

 

 

 

 

 

 

 

 

(The B  Major chord will be tricky too: B , D, and F; in other words, chocolate, vanilla, vanilla.)