Changing Notes chords

You can create chords and intervals using the number keys along the top of the keyboard. The 3 key makes a third, the 4 key a fourth, and so on. Shift+3 gives you the 3rd below.

You can toggle selection to individual pitches by using Shift+UpArrow. So to create a G triad, starting with g, hit 3 for the 'B', 3 again for the 'D'. So far, we have G major. To lower the 3rd, Shift+up to select the 'B', then - to lower the pitch.