Boston Calling, Boston’s major music festival that will be a bi-annual City Hall Plaza staple for at least the next three years, is officially announcing its May 2015 lineup tomorrow. But, we can count on finding out the full list of scheduled artists tonight. The festival is reinstating its “Find the Vinyl” contest tonight, a scavenger hunt throughout the city that will culminate in two late night parties, where the lineup will be announced via video.

The clues for the scavenger hunt will be released on Boston Calling’s social media pages (Facebook and Twitter) and its website tonight at 5:45 p.m., and from 6 to 8 p.m., fans are invited to follow the clues and search the city for one of the 11 vinyl records tucked around town. Each vinyl will reveal just one artist of the 23 scheduled to perform at this year’s festival; this is opposed to last year’s “Find the Vinyl” contest, when each vinyl was scripted with the full lineup.

Once a vinyl is found, the lucky fan must share a photo of it on social media with the hashtag #bostoncalling by 8:30 p.m. The winners will get to keep the vinyl, as well as receive two three-day General Admission tickets for the upcoming festival. Tickets will go on sale for the public tomorrow, January 14, at 10 a.m.

Following the scavenger hunt, Boston Calling will celebrate with two late-night parties at both Tasty Burger locations in Fenway and Harvard Square. The parties, which begin at 9 p.m., are free and open to the public, and at 9:30 p.m., the festival team will screen a video announcing the May 2015 lineup in full.

This year, the lineup stems from a different source. Following September 2014’s festival, Boston Calling’s production company, Crash Line, parted ways with its booking agency, Bowery Boston, in favor of an in-house booking format. We’ll have to see how the May festival’s artists compares to lineups of past.

Stay tuned till tonight!

For photos from the September 2014 festival, click here.