A new collaboration by Adrián Juárez and Juan José Calarco provides one of those situations wherein the sum of the parts is considerably less than the constituent parts themselves. Except in this case, that statement is not just a compliment; it’s a formal measure of the duo’s accomplishment. The material that Juárez and Calarco plumbed for their 14-minute soundcape, titled “Tierra Abierta, is, self-evidently, field recordings — rain and wind and other real-world noise working together to form an artificial but semi-natural realm (MP3). Only with repeated listens can the attention to balance between those elements can be appreciated, as can the means by which apparent light processing has allowed looped elements to yield rhythmic and compositional impact. More information at the website of the releasing netlabel, restingbell.net. Don’t turn it up too high, as there is one loud moment, but it serves primarily to emphasize the relative quietude of the rest of the piece.