Noteworthy Composer?

NWC has a pretty comprehensive help system. Have you tried typing <F1> within the program?

For chord entry (notes vertically aligned and played at the same time):

1. Enter the first note of the chord.

2. Position the insertion point to the right of the note and at the pitch for the second note in the chord.

3. Press Ctrl+Enter to place the second note in a chord with the first note.

4. 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.

Intro: (Not the answer) Typically up and down stems within the same staff indicate separate voices. Choral (SATB) music it is often noted on two staves with the Soprano/Alto on the top, and Tenor/Bass on the bottom. Stems for Soprano and Tenor will be up, Alto and Bass will be down. (the answer) Knowing "voices" (above) to write piano (or other polyphonic) music, you'll want the stems facing the same direction. The trick is to having all the notes that move together in the same voice. I don't know how NWC does that, it might be by building a "chord" by adding intervals above or below the note that is already on the staff, or you may be able to do it globally after-the-fact by highlighting the measure (or individual notes) and force them to be in one voice or the other by a menu pull-down. (These are the ways that Sibelius allows you to change voices) ... wherever you have poly rhythms (say, eighth notes above a quarter note) you'll still want the stems up/down arrangement since that is easier to read than having moving eighths above a set of tied eighths.

I can explain it for piano and guitar, but with Noteworthy Composer? If it's a computer program, you're probably better off just getting a musical staff notebook and writing it out.

That's how Bach did it.