Tom Petty changed the lyrics to the Bob Dylan classic "Knockin' on Heaven's Door" in the wake of the mass shooting in Orlando last weekend. You can see it at about the four-minute mark in the fan-filmed clip above.

Petty, performing with his revived pre-Heartbreakers band Mudcrutch, played a version of Dylan's 1973 song midway through his set last night at the House of Blues in Boston. In the third verse, he notably altered Dylan's original line of "Ma', take my guns and put them in the ground." In the new version, Petty replaced "guns" with "automatic weapons," a clear reference to the tragic events that unfolded at a gay nightclub in Petty's home state of Florida.

At least 49 people were killed in the rampage, with many others still clinging to life. The incident has sparked a wave of responses from other musicians.

Petty has often found a place for "Knockin' on Heaven's Door" in his concert sets, including recent Mudcrutch stops at New York's Webster Hall and Philadelphia's Fillmore – though there haven't been reports of any lyrical updates at those shows. Mudcrutch, whose members also include Mike Campbell and Benmont Tench from the Heartbreakers, will next appear in San Francisco on Sunday.

Petty memorably toured with Dylan in 1986, just before they co-founded the Traveling Wilburys supergroup with George Harrison, Jeff Lynne and Roy Orbison. Petty's 1987 album, Let Me Up (I've Had Enough), included the song "Jammin' Me," which was co-written by Dylan.

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