While I wouldn't call it a "classic", the song they are covering is classic Metallica and a great one. Dream Theater, the band covering it, did a pretty decent job on the music, but the singer was just hideous. It's obviously just not his vocal range or style and make the song just unbearable to listen to.
Dream Theater does have some cool songs though from years gone by. Check out "Pull Me Under" from the little video menu at the bottom of the player if you want to hear one of their better ones. They have an eclectic style, but some very good musical talent in the group. I haven't heard any of their recent stuff though - just a few albums from the late 80s - early 90s.
Definitely a classic song. Too bad that singer sux. The instrument portion is nice. Brings back good memories of a magical time when "the black album" was awesome and Metallica was still hard. Saw them in concert twice in Houston. Once in the Astrodome back in '93 with Faith No More and Guns & Roses. Saw them again at the Houston Raceway park sometime a year or two later. Made it to the front row both times nearly getting smashed in the "mosh pit" scramble. Got my foot stomped and my neck bashed from so many crowd surfers coming over from the back. Nearly caught a guitar clip from the band. I never really cared much for them after that next album came out. Can't even remember the name anymore, but it sure seemed like they got old or simply just couldn't "do it" anymore.
I still have the shirts from the first concert. One is of Metallica and Guns & Roses. The other is "Don't Tread on Me" by Metallica.