Two summertime favorites square off against each other in the first round of Ultimate Classic Rock's quest to find the Greatest Summer Song. You can vote for either Led Zeppelin's "Dancing Days" or the Seals and Crofts' "Summer Breeze" below.

We’ve selected 32 of classic rock’s best summertime songs, and paired them off in 16 first-round duels. Over the next five weeks the field will be repeatedly cut in half by your votes, until we arrive at the greatest summer song ever made.

"Dancing Days" first appeared on Zeppelin's 1973 album Houses of the Holy, and states its motive from the very first line: "Dancing days are here again, as the summer evenings grow." It's lighter than many of the blues-inspired songs that came before it in the band's catalog, an ode to love (or, rather, sex) during the long summer months. During their first tour, Jimmy Page used to play another summer song, the instrumental "White Summer" (a holdover from his Yardbirds days) in a medley with the debut's "Black Mountain Side."

Sex isn't quite on the mind of the guy singing Seals and Crofts' 1972 Top 10 hit, but we're betting those arms reaching out to him "in the evening when the day is through" could lead to some lovin'. The soft-rock perennial sounds like summer, from the simple piano that helps guide that unforgettable melody to the sweet harmonies of the duo that wrote and sang the song. Plus, it's filled with the sort of jasmine-scented summer memories we hope to never forget.

So which one will earn a trip to the second round? Listen to both below and make your call. You can vote once per hour in each of the 16 first-round Greatest Summer Song battles until voting closes on July 27 at 11:59PM ET. Your choice for the Greatest Summer Song of all time will be revealed on Aug. 25, 2015.

Listen to the Led Zeppelin Perform 'Dancing Days'

Listen to Seals and Crofts Perform 'Summer Breeze'

See Led Zeppelin and Other Rockers in the Top 100 Albums of the '70s