Here you will find some of the Plainsong Chants use by Fr Terry at Masses. You may find that your Missal will have the music in it. However some is provided as links on this page.
Memorial-Acclamation
Mystery-of-Faith
https://www.stmaryoftheangels.org.uk/wp-content/uploads/2015/12/Memorial-Acclamations.pdf
Agnus-Dei
https://www.stmaryoftheangels.org.uk/wp-content/uploads/2015/12/Sanctus.pdf