here is a few ideas for creating a music lesson plan about percussion instruments.
To help students understand how timpani can be tuned, demonstrate the effect of membrane tension on pitch. With a simple home made drum, pull on the edges of the drumhead to put varying degrees of tension on it, while a student plays a steady drumbeat on it. Students can get into pairs and take turns exploring the effect of tension of skin on the drum’s pitch.
Have a look at the keyboard percussion instruments, the xylophone, marimba and Glockenspiel, and show the students how they are laid out just like a piano. Have students make a “paperphone.” Students can cut out rectangular bars of continually smaller sizes out of paper and glue them to thick cardboard or a large sheet of paper. Label the bars with the appropriate note names.
Demonstrate how resonance can amplify the sound of an instrument. Take an individual bar from a xylophone or Orff instrument or something similar and strike it both by itself and over a a hollow tube (e.g., PVC pipe). It may necessary to have a go first with the instruments around the school first to make sure you can clearly demonstrate this using your instruments.
Here is a great recording to check out: Béla Bartók, Music for Strings, Percussion, and Celesta, III. Adagio. This movement has prominent parts for xylophone and timpani. The timpani performs glissandi throughout, an excellent demonstration of its pitch capabilities.