Two bands that mined the music of the American South in different, yet equally classic, ways are vying for their shot at rock immortality. The Eagles and ZZ Top meet in the semifinals of the Ultimate Classic Rock Hall of Fame.

The Eagles’ original tenure only lasted seven years, but the six albums they made in that time defined the ‘70s L.A. sound. Their music was a smoothed-out hybrid of country and rock topped with pitch-perfect harmonies, while their lyrics chronicled the decadence of the Southern California lifestyle. Since reuniting in 1994, they’ve mounted several successful tours and released a couple of chart-topping albums. They defeated Thin Lizzy in the first round of our Hall of Fame voting by a respectable 57% to 43% margin.

ZZ Top, on the other hand, took a few albums to find their groove, but never let up once they did. Thanks to Billy Gibbons’ mastery of tone, taste, tenacity and most importantly, his use of double entendres, they went from a Tex-Mex blues band to one of the ‘80s most reliable hit makers -- modernizing their sound with synthesizers without ever losing sight of the importance of the boogie. They dispatched a very hard-fighting Blue Oyster Cult in Round One of this month's voting.

Which one will make it to the final round? You can vote once a day until Sunday, Dec. 22, at 11:59 PM EST, and the winner will be announced Jan. 6, 2014. Be sure to read our official rules here.