Mr. Hirasawa has recorded this tutorial for some of his students and was kind enough to share it with us.
In this video he explains what hardware and software you need on your Mac in order to successfully route audio from your digital instruments to your computer for online music lessons and just for fun! He also covers the logic behind audio routing so that you can troubleshoot any problems you may have with audio routing on your own! Enjoy! https://youtu.be/Z-E_MLJ6tvk