When rock band X Japan finally made its live U.S. debut, its most beloved member wasn't there.

When X Japan, one of Japan's most successful rock acts, finally made its live U.S. debut in Chicago at Lollapalooza 2010, its most beloved member wasn't there.

X Japan have sold more than 30 million albums since the band formed back in 1982. Influenced by glam and heavy metal bands, they are credited with launching the visual-kei movement, a Japanese musical genre that fuses goth, punk and heavy metal, places a strong emphasis on theatricality, and includes lots of big hair and flamboyant, androgynous costumes.

Hideto Matsumoto – known to fans simply as "hide" – was the band's lead guitarist at the peak of its powers and also shared songwriting duties. A fan favorite, he also enjoyed a successful solo career, working on side projects with members of American acts Danzig and Ministry, among many others.

In 1998, X Japan took a hiatus while its various members explored such solo projects. In May of that year, Matsumoto was found hanged by a towel tied to the doorknob of his apartment in Tokyo. No suicide note was left, and his bandmates believed the death to be an accident. He'd been drinking heavily the previous night, and the position his body was discovered in reminded his bandmates of an exercise he often practiced on tour to alleviate stress on his neck and shoulders, one which involved suspending his upper body using towels anchored around a doorknob.

The staggering outpouring of grief for Matsumoto was like nothing Japan had ever seen. Fifty thousand people attended his funeral. Nearly 60 had to be hospitalized and at least three fans died in copycat suicides. His posthumous single "Pink Spider" raced up the Japanese charts, and a museum was dedicated to his memory in his hometown of Yokosuka.

On Aug. 8, 2010, when X Japan took the stage at Lollapalooza to adoring fans who'd traveled from far and wide to see this legendary act make their full North American debut, they made it clear they hadn't forgotten the guitarist who'd left them 12 years ago, paying tribute to Matsumoto in a video montage during their set.