It's Beantown vs. Tejas as ZZ Top's 'La Grange' faces off against Boston's 'More Than a Feeling' in round one of Ultimate Classic Rock's March Riff Madness competition.

It wasn't easy, but we’ve selected 32 of classic rock’s most iconic riffs 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 theoretically arrive at the most awesome riff in all of rock history.

Neither of these songs need much in the way of introduction. But if you can't somehow conjure up the riff from ZZ Top's 'La Grange' in your mind right this second, we strongly suggest you grab a copy of 1973's 'Tres Hombres' right this second. The exact same advice goes for the lead-off track from Boston's classic self-titled 1976 debut.

So all that's left is for you to decide which of these awesome riffs moves on to the next round. You can vote once per hour until round one of our March Riff Madness voting closes on Sunday, March 9 at 11:59PM ET. The ultimate winner will be revealed on April 7.

March Riff Madness USA Bracket

Watch Boston Perform 'More Than a Feeling'

Watch ZZ Top Perform 'La Grange'

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