I always find the first meetings a time of great hope and excitement as the student teacher looks forward to putting into practice all the things she/he has learned in the courses they have taken in previous semesters. We talk about the expectations for the semester, the lesson plans and instructional unit the student will need to complete, their commitment to student teaching as a full-time activity for the semester, the expertise the cooperating teacher will share them, and the need to make sure that they let the students they are working with know they care about them.
My four student teacher span the elementary grades from kindergarten to fourth grade this semester which is a wonderful experience for me. I often think it would be neat if public school teachers got to share this wonderful experience I have of working in so many different classrooms with so many inspirational teachers.
A triad in music is an "implied harmony". I can't think of a better metaphor for the student teaching experience.