Difference between a progression and phrase generator?

[rcook]

I've create a composition from a chord progression, I end up with something like the following:

progression.png

i.e. The progression creates a new composition with the specified chords and creates a single track with a single held chord for each bar - although in the phrase editor the notes appear as quarter notes, so - somehow - they are being held or tied together,

If, on the other hand, I delete the automatically generated track with an empty track and drag the "Chord Generator" from the phrases palette, I end up with the following:

chord-generator.png

i.e. Chords played in quarter notes following the master chord progression. However, this time the notes are not held or tied together.

What are the differences between the track created by the progression and the track filled by the Chord Generator? How do I use Chord Generator to generate "held" chords like the progression generator?

Update: I think I figured it out. This is caused by the "Join Notes" variation accessible from the track inspector's "Variations" tab.