There are jam sessions, which I always liked the idea of. Just jamming away, expressing creatively what’s on your heart, using instruments, be that a piano, a guitar, a drum. I reckon I have more writing jams than musical ones, although music and writing tend to intersect in some loose ways. Just pouring it all out over the keyboard without thinking about how it sounds or the structure. Anyhow, jams always sound good.
These days my writing sessions are shorter and more deliberate as I focus on one or two genres, write the rough drafts, edit thoughtfully, and watch it unfold. Short sessions, but productive and hopefully finding a place with a publisher.