I just went through this for MM Plus 2019. Open your MM, in upper right corner there are tabs for loops (soundpools) and instruments. Click on instruments, and a bunch of choices should appear. When you see a lot of instruments listed, click in the middle of the graphic to hear how it sounds, click again to stop play. Also, be sure click on the "i" inside white circles for more info about each instrument, including purchase price. When you are sure you want to purchase a particular instrument, click on "purchase" and a window should pop open listing the name of the instrument and the cost. For me the cost was 0 for my initial free ones. Hope this helps. And as Graham-Hawker stated, there's an an option to redeem coupons if that's what you have, and be sure you are logged into your account.