Heart and Boston both made fairly quick work of their opponents in the first round of voting for the Ultimate Classic Rock Hall of Fame, but it isn't time to pop the champagne just yet. Now that they've moved on to the semifinals, they're facing off against each other, and only one band will make it to the next round.

Heart rocked past John Mellencamp in the first round, earning an impressive 65 percent of the vote, while Boston defeated Rainbow by an even wider margin, walking away with nearly 70 percent. Something tells us the race is bound to be a little tighter this time around.

Both bands have been active since the '70s -- and they both became household names in the United States in 1976, when Heart's 'Dreamboat Annie' LP, issued the previous year in Canada, invaded these shores and spawned a pair of Top 40 singles ('Magic Man' and 'Crazy On You') on its way to a Platinum sales certification from the RIAA. Boston, meanwhile, was one of the year's biggest success stories, with its self-titled debut LP arriving on Aug, 25 and spending the first of a whopping 132 weeks on the charts; behind the classic singles 'More Than a Feeling,' 'Long Time,' and 'Peace of Mind,' it ultimately went on to move more than 17 million units.

Heart has worked steadily over the years, reinventing their sound for a string of hit records in the '80s before returning to their rock roots for a recent series of successful albums and tours. Boston has become known for taking long layoffs between albums while meticulous frontman Tom Scholz ensures each track meets his standards of approval, but the current incarnation of the group is still very much a going concern; in fact, they're in the midst of an extensive tour in support of their most recent album, 2013's 'Life, Love & Hope.'

So which of these legendary rock groups will make it to the next round? That's all up to you, and you can vote once an hour between now and Sunday, June 22 at 11:59PM Eastern. The next inductee into the Ultimate Classic Rock Hall of Fame will be announced on July 1. Be sure to read our official rules.