Choosing a monthly focus topic for piano lesson not only simplifies lesson planning, but it also helps me ensure that students are getting a well-rounded exposure to musical concepts that can easily be overlooked like composition and ear training.
Group lessons in my studio are often centered around a certain concept although I periodically do a Mash-up or Holiday Themed Review Group lesson to touch on multiple concepts. I incorporate activities in weekly private lessons to go along with the theme that are customized to the level the student is currently on. Often I will give the students a challenge to go along with monthly theme and they love the recognition of being added to the leaderboard. These include both short term goals they can achieve in one week like the Crazy Chord Challenge and Thumb Tuck Challenge, and longer term incentives like Bulls-Eye Practice, Piano Tracking, Candy Jar Challenge, Piano Mountains.
Following are links to my group lesson plans and activities that I have used the past few years.
Practice Themed Group Lesson
Valentine's/Composing Group Lesson
Piano Technique and Artistry Group Lesson
Music Theory Carnival Games
Ear Training Group Games
Summer Piano Synergy
Halloween Group Activities
Theme and Variations Form and Composing
Basic Accompaniment Skills
Christmas Themed and More Christmas Group Activities