Created by great geniuses

I am fun and sad. I am fast and slow. I get louder and I get softer. And I am created by great geniuses. What am I?

Ultimate killing machine

I am the ultimate killing machine, used not once but TWICE, I can be made by humans. What am I?

Travels in a gaggle

I travel in a gaggle. What am I?

I am commonly abbreviated to H

I am commonly abbreviated to H. What am I?

Strawberry to toe

My flavors range from strawberry to toe. What am I?