How do you change the pitch of a glonkspiel?

To change the pitch of a glockenspiel, you can adjust the length and thickness of the metal bars. Shortening the bars or using thinner materials will raise the pitch, while lengthening them or using thicker bars will lower the pitch. Additionally, positioning the bars at different points on the resonator can also affect the sound quality and pitch produced. Tuning can also be fine-tuned by removing material from the center or ends of the bars.