There has to be some sense of security before you can create. Just like my student who needed the security of that one note. Just like I needed the security to know I could fail. You need the security of trusting your team. Why would anyone want to share their ideas with people they didn't trust.
Groups are successful when the whole is greater than the sum of the parts.
It's something magical. When you're on the right team, when you trust, you find that you can rise above yourself. You're really listening, you're really taking everything in. You're no longer thinking just about yourself. Just because you might use other's work as a springboard for improvisation, that doesn't mean you should be confined by what others have done.