They're the most overplayed songs known to man, but there's a reason Lynyrd Skynyrd's 'Free Bird' and Led Zeppelin's 'Stairway to Heaven' still dominate classic-rock radio 40 years after they were released: They're awesome! And now it's time for you to choose one as the victor in this week's Clash of the Titans.

'Free Bird' was the set piece to Skynyrd's classic 1973 debut, 'Pronounced Leh-Nerd Skin-Nerd.' The original studio version of the song clocks in at an economical nine minutes. In concert, 'Free Bird' would break the 15-minute mark, taking fans on a quarter-hour odyssey from flicked lighters to raging air-guitar solos.

Likewise, Zeppelin's 1971 classic (from their equally titanic fourth album) begins as a ballad before breaking free of its acoustic chains and unleashing a full-on blitzkrieg of searing guitars. 'Stairway to Heaven''s eight-minute studio version is nothing compared to the epic length (15-plus minutes) the song would take onstage.

If you need to do some research before you cast your vote at the bottom, listen to both songs below (for what we guess is like the gazillionth time). This Clash of the Titans will stay open until Feb. 11, 2014. You can vote once a day for your favorite.

Lynyrd Skynyrd's 'Free Bird'

Led Zeppelin's 'Stairway to Heaven'