If you've accomplished steps 1 and 2 than you have trained your ear to directing your buzz to play whole steps and half steps. Now stretch your ear further and pick a song to buzz. This is a fun example of Denis Wick artists from the Alliance Brass Quintet performing Happy Trails in 4 part harmony during a long drive on tour.
To start, try buzzing Row, Row, Row your boat. Once you've accomplished that, find a friend who is working on the same exercise, and buzz it in a round!
Other easy songs you might want to start with are Twinkle Twinkle Little Star, and Happy Birthday. Work on buzzing the right note immediately as opposed to scooping into the note. Always play your starting note first on your instrument so you can test if you ended on the right note, jus tlike you did in steps 1 and 2.
If you record your buzzed masterpiece for social media, make sure to post it with #teamdeniswick so we can see/hear your creation too!