Finland is home to a flourishing circle of improv jazz musicians. The latest CD from that floating cadre opens in fractured waltz time; one could imagine a couple, weary from sleeplessness and liqueur, dancing clumsily around the tiny floor of a broken-down café. Likewise, the smudges of brass and abstract grooves elsewhere on Rubidium are in search of familiar melody and rhythm as well as the silent spaces in between sounds.