A pair of '70s soft rock classics face each other in the first round of Ultimate Classic Rock's quest to find the Greatest Summer Song. You can vote for either Billy Joel's "Summer, Highland Falls" or Chicago's "Saturday in the Park" 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.

Joel wrote "Summer, Highland Falls" in 1975 after settling in the upstate New York small town upon returning from a few years in Los Angeles. It was released on his 1976 album Turnstiles, which failed to capture an audience. However, it received a new life when a version recorded at Washington, D.C.'s, late, lamented Bayou club surfaced on 1981's Songs in the Attic, and has since gone on to become one of his most beloved deep cuts.

"Saturday in the Park," from Chicago V, reached No. 3 on the Billboard Hot 100 in 1972, making it their biggest hit at the time. It was written by Robert Lamm, who sings lead to start the verse, with Peter Cetera taking over the vocals for the b-section. Coincidentally, James William Guercio produced Chicago V and was originally hired to produced Turnstiles. But the sessions didn't go well and Joel wound up producing the record himself.

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 Billy Joel Perform 'Summer Highland Falls'

Watch Chicago's Perform 'Saturday in the Park'

See Billy Joel and Other Rockers in the Top 100 Albums of the '70s