Acapella presents clips from a stock-footage library, still bearing their time codes, of objects such as an apple, a basketball, and a burgeoning pile of popcorn, morphing over chroma-key-ready single-color backgrounds. Lonergan sets this collection to Sting’s a cappella version of the Police’s “Message in a Bottle.” That song’s refrain of “sending out an SOS” seems to echo Lonergan’s Web collage brb, 2008, made from merely two elements: the lowercase letters of its acronymic title, scrolling right to left, placed over an embedded, looping sound file of what one at first assumes to be the Morse-code distress signal (three short, three long, three short), but upon careful listening discovers to spell out “brb” (one long, three short; one short, one long, one short; and one long, three short). Be right back.