If they did something positive, like play a line of music correctly etc etc. They got a plus . Which was two points added. So they got the chance to make up for there not participating correctly.
It didn't take long for the students to realize that when I grabbed the clip board , I meant business and they stopped talking. If they got more that one check in a day or 3 checks in a week. I contacted the parent. You are going to have some defiant ones, but stand your ground and follow your district's discipline plan.
A good friend of mine showed me this system and I got results. Find what works best for you.