Each day's gift can be discovered by using Apple's 12 Days of Gifts app available for iPhone, iPad and iPod touch. Monday's offering, the New Years Eve Mix single from Avicii, can also be downloaded for free directly from the iTunes Store.
The single includes the music video for Avicii's smash hit "Wake Me Up." The same track is included in a special New Years Eve mix by the DJ, which also features the songs "Hey Brother," and "I Could Be the One."
The single was previously priced at $4.99, but is free for Tuesday only. As the sixth gift, the Avicii track and video mark the halfway point of Apple's "12 Days of Gifts."
Apple's gifts have varied by country and region, but Tuesday's track from the Swedish DJ is available for free in both the U.S. and the U.K.
Monday's free gift in the U.S. was Oscar-winning film Hugo, from director Martin Scorsese. U.K. users received a free copy of the holiday classic Home Alone.
Other previous U.S. gifts from Apple include a Justin Timberlake single, the iOS game Tiny Thief, Lonely Planet's Best in Travel 2014 e-book, and a single from Lorde.