Heavy metal has seen a lot of changes since Megadeth delivered its thrashy debut album, Killing Is My Business.. And Business Is Good!, back in 1985. Nowadays it includes death metal, black metal, speed metal, thrash metal, power metal, pop metal, alternative metal, nu metal, and metalcore. But according to Megadeth founder and singer-guitarist Dave Mustaine, there's a common bond that keeps the genre popular. "Let's go back to where it's just metal," he suggests, on the line from his band's office in Fallbrook, California. "There's a common theme for all of these bands, and what is it? It's guitar. Love that!"

Like the majority of its ear-busting brethren, Megadeth has made its name with intense fretwork, over the years enlisting such primo pickers as Chris Poland, Marty Friedman, and Al Pitrelli. The serious shredding continues on the group's 11th studio album, United Abominations, set for release this May. On it, Mustaine trades blistering solos with former King Diamond and Eidolon guitarist Glen Drover, who joined the band in 2004. "He's a better guitarist than I am," notes Mustaine, "but the beauty of having Glen Drover play with me right now is basically like [racehorse] Seabiscuit, you know-he just needed to have that amazing talent focused."

United Abominations continues main songwriter Mustaine's practice of raging, via thrashy yet melodic hard-rock, against the abuse of power, and its corrupting influence. The cover illustration portrays the United Nations building being bombarded by fiery drums of petrol. "Those are barrels of oil that they were trading," he explains, "í¢â‚¬”°'cause it's the oil-for-food scandal with Kofi Annan's son. The barrels are lit on fire and they become the very undoing of the U.N."

Besides new, politically fuelled tracks like "Washington Is Next!" and "Amerikhastan", the upcoming disc includes a reworking of "A Tout Le Monde", which originally appeared on the 1994 CD, Youthanasia. The remake has created controversy because the song was cited in an on-line post by Dawson College killer Kimveer Gill as one of his favourites before his Montreal shooting spree last September. Mustaine contends that he wanted to give the song a second shot at success, as the original video for it had been banned by MTV, and most radio stations followed suit. The track ended up featuring Cristina Scabbia from Italian alt-metal act Lacuna Coil. "The first singer didn't work out," explains Mustaine, "the second one didn't work, and the third one was Lisa Marie Presley. She was on the way to the airport, and we had to call and say, 'Sorry, we changed our minds.' I would have loved to have heard what Lisa Marie Presley would have done, but because of the demographics of the Lacuna Coil fan base, and Cristina's reign in the heavy-metal business, it was the right thing to do."

Megadeth will be showcasing songs from United Abominations on a Canadian tour with Heaven and Hell, the post–Ozzy Osbourne lineup of Black Sabbath. "My favourite song by them was 'Never Say Die'," he explains, referring to the title track of Sabbath's final album with Osbourne. "I wasn't really a big fan of the other stuff because it was so unbelievably heavy at the time, and I was just a kid...I went back through the catalogue and that's when I discovered how great they were."

Megadeth opens for Heaven and Hell at the Pacific Coliseum on Sunday (March 11).