I talkek to Apple Tech Support about GarageBand today about system requirements. They haven't had time to test the product themselves since they don't actually have the product in hand. However, the man told me that on this sheet of paper of the current tech support troubleshooting that GarageBand may require a G3 or more. So it may work on a G3 if it is more that 600 MHZ. Maybe. Here's hoping that it will work on my iBook G3 700 MHZ