A trademark filing in July outed Harmonix's next project, an iOS app called Vidrhythm, with the developer at first refusing to reveal anything about it beyond a curt "it will be awesome" and later moving to correct reports that described it as a game instead of an app. At last weekend's PAX event in Seattle, Vidrhythm was formally unveiled as an earnestly lo-fi music video generator: it records a succession of short video clips of users making various sound effects and stitches them together. As IGN's report shows, there's clear potential for some clever creations in the right hands - and some frankly nightmarish efforts in the wrong ones.