Jam Sessions/Open Mic are held regularly every four to six weeks at my studio where I give lessons. They are usually held on Friday nights from 7pm to 9pm. I have a drummer and a bass player and all of my students are welcome, along with their guests, free of charge. Only my students are invited, so the atmosphere is one of low pressure and fun. Everyone is just getting started and it is perfectly OK to make mistakes or be nervous, I promise you wont be the only one. I try to provide a nurturing learning environment where everyone feels comfortable to play and ask questions. Everyone is encouraged to play but some students just come to hang out as well. Usually, a few students will bring food and beverages for everyone to share, and that is much appreciated.
I have many students who study blues and lead guitar and there are many opportunities to improvise solos or play chords. I always try to help the players figure out which scale to use and what key to put it in. Sometimes we write chord progressions on the white board and talk about how to improvise over them. Many students also play acoustic guitar and can perform covers they have learned or even original songs. I have a great PA system and microphones and even percussion instruments that guests can bang on. Jam Sessions exist for my students so they are the ones who decide the direction they go in and they are always open to suggestion. Its also a great way to meet other musicians who live in the area.