Psalm Tones: Recto Tono and In Directum

Here I make a start on a plan to explain how to sing the psalm tones for the Little Office of the Blessed Virgin Mary.
I start with the two simplest tones - Recto Tono and Tonus In Directum.
The Tonus In Directum is used in the Little Office for the three Psalms in the hour of Compline.
Here I'm using the Monastic version, but the Roman version is very similar.