Every weekly post of Jamming Zone has a brief introduction about the event and it explains it is about improvisation or "jams" wich are very common in blues/jazz and many other style of music, improvisation comes up when you just play what youre feeling in the moment with no previous structure or music writing, let´s say you have a backing track in C major and you just jam along with it playing the C major scale and its relative A minor and pentatonic scales for example, you create your own melody in real time without previosu preparation thats basically what it´s about, you can do it over a rythmic base made of your own or a backing track, or simply impovise on any instrument without any backing, the idea is to stimulate creativity by performing original tunes on the go ... you can find some good examples on other entries, and maybe in one of my own videos, i have long time without posting anything tho ... big hug brother! many blessings for you =)