Ok, so one really effective and easy way at reducing the number of temper tantrums your toddler is having is simply to talk to your toddler about his/her day. One of the reasons toddlers have so many tantrums is that they have no control over their lives, they are abruptly moved about from place to place with no warning.
He doesn't know why you suddenly picked him up and tried to put on his winter coat when he was having a good time playing with his toys, or why after he enjoyed that cookie so much you won't give him another one.
Your toddler understands a lot more than he/she can actually speak. Even if your toddler can't speak at all yet, he will understand you if you talk to him. Give him a 10 minute warning before you take him out of the house for music class. Explain before you give him his first cookie that he will only have one.
Try something like this:
Christopher, we are leaving in 10 minutes to go to music class. I am going to put on your jacket, your socks and shoes. Then you should let me put you in your stroller without fighting me. We are going to walk to music class and I'll give you a snack of cereal while you are in your stroller and then you will have fun at music. 
Jack, I am going to give you one cookie now. After you eat this cookie there are no more cookies for Jack. Jack gets one cookie, then you can go play. 
If you are not used to talking to your toddler in this way, I know it may feel strange at first, but once you start doing this you really will see better behavior in your toddler. And as an added bonus, it will help his language development.
Other good times you can "talk" to your toddler are:
- First thing in the morning you can talk about what activities you will be doing that day
- Before bed you can talk about what activities you will be doing the next day
- In the car while driving you can talk about where you are going
- During meal times while he is in his high chair and you have his attention
I would love to hear if this technique is successful for you. Try it out for a week and come back and leave a comment letting me know. Also stay tuned for more articles in this series about temper tantrums, and sign up for the newsletter if you would like to be notified when more articles are published.