I want to do this. I WANT TO DO THIS. Let’s do this, you mokes. This is your official invitation to Songs of Good Cheer, the holiday singalong that my colleague Eric Zorn and I are hosting for the 13th straight year. Sorry for mentioning Christmas in October, but there are a lot of hyper-organized holiday lovers out there who make plans long before the last leaf falls. So here’s everything you need to know to join us. We hope you will. Who: A band of first-rate musicians from the Old Town School of Folk Music whose instruments include banjo,…