For chord entry (notes vertically aligned and played at the same time):
Enter the first note of the chord.
Position the insertion point to the right of the note and at the pitch for the second note in the chord.
Press Ctrl+Enter to place the second note in a chord with the first note.
Repeat steps 2 & 3 to add more notes to the chord.
You can remove a chord member by positioning the insertion point to the right of the note to be removed and pressing Ctrl+Backspace. For more information on chords, search the NWC Help file for Chord Member Command.
For entering two voices on a staff, you will need to use Staff Layering. See faq #24, "How are 2 voices on a staff notated (satb)?" for details on using Staff Layering