There's epic adventure in the works in Oakland this weekend with two consecutive nights of world-class jazz improvisation. First up: drummer Han Bennink, Dutch pioneer of the "free music" movement of the 1960s, and celebrated pianist Myra Melford, a 2013 Guggenheim Fellow. Then clarinetist Ben Goldberg, a veteran Bay Area composer-improviser who's been directing awesome big-band compositions lately, and Mary Oliver, an international new music master. The concept at play here is that everything about these performances will move — fluid melody, harmony, and rhythm; no boundaries; no fear. The aim is for the music to excite and surprise both listeners and players.