OK Go

OK Go gives fans a free iTunes download if they get their friends to play the silky disco-pop single “A Million Ways” in its entirety. (The online Web site for this promotion is a1000000ways.com; the more convenient spelled-out version belongs to a cryptic place-holder site.) It’s a pleasant task to complete; the tune is three minutes long and hooky as hell — which could also be said about any of the equally appealing 13 tracks on OK Go’s August release, Oh No. It’s a fair bet that many ensnared acquaintances will use their gratis download on another OK Go song, uncovering piano pop, tart new wave or cowbell-pummeling garage rock. There’s no tangible incentive for persuading buddies to check out OK Go’s live show, but if they enjoy any melody-driven music from the past two decades, they’ll probably appreciate the tip so much that they’ll spring for the post-show snack.