The bass tone is played by hitting the center of the drum with your open hand. You want to bounce your whole hand against the skin to get that deep, low pitch. Also, by bouncing your hand off the head of the drum, the tones are left to resonate. Start by practicing this bass tone a few times — this is your core.
Modes and Key Signatures have a variety of different characteristics and are great for outside-the-box songwriting. Here’s a cheat sheet to remember them!