NtEd places the beams automatically depending on the note length and the time signature. This works in most cases. But sometimes the user wishes costumized beams. To change the beaming make the more acc. toolbar visible. To do this choose:
→
The more accidentals toolbar appears:

The more accidentals toolbar has a button which changes its appearence depending of whether there
is a selection rectangle or not (see Select a block). If there is no selection rectangle the button isolates a currently beamed
note (
).
To isolate make sure NtEd is in edit mode (see The 3 modes). Select a beamed note by left clicking it:

Then press the isolate button (
):

The note is isolated.
To connect some notes with a beam, select them as described in Select a block:

The button changes its appearence (
).
Press the button and NtEd connects the notes by a beam:

Note! This function can break beams as well, if the selection rectangle crosses an existing beam:

This results in:

Instead of pressing the button you can use Ctrl-J independend of the button's appearence.