Minneapolis was abuzz with a series of teaser ads earlier this year, each bearing a rock-and-roll theme.

One ad featured a woman holding no ordinary piece of toast, but one containing an image of a burned guitar. Another ad showed a man holding an adorable kitten with the "rock on" hand etched into its head. A figure playing a guitar was found in the knot of a two by four in the final ad.

"It's a sign. Make the pilgrimage," said the branded ads that replaced teaser spots encouraging concertgoers to attend the local Basilica Block Party. This event took place on the grounds of The Basilica of Saint Mary's, the oldest Basilica church in the country, making this event a religious pilgrimage of sorts.

OLSON created the campaign and handled the media buy for the outdoor campaign that ran in the Twin Cities metro area.

If passers-by didn't see the message in phase one of the campaign, perhaps phase two spoke to them... literally.

According to Tom Fugleberg, executive creative director at OLSON, the agency "used hypersonic sound cannons on the streets of downtown that fired audio messages at specific individuals in a crowd so that only those individuals hear the 'audio apparitions' we were projecting. Certain people would hear the music from the block party's line-up in their heads, and the message, 'If you hear this, it's a sign.'" Indeed it is.