Kurt Cobain's searing voice was an integral part of Nirvana's sound -- and isolated audio of the late frontman's vocal track on their signature song, 'Smells Like Teen Spirit,' proves just how true that was.

Without Dave Grohl's pounding drums or Krist Novoselic's bass to distract you, Cobain's vocals sound almost melodic, but never lose the haunting edge for which he became so famous.

Dropped as a single on August 21, 1991, 'Smells Like Teen Spirit' was the first -- and biggest -- track from Nirvana's multi-platinum album 'Nevermind.' The band recorded the song with noted producer Butch Vig a few months earlier, and while Cobain had a well-known disdain for repeated takes, Vig said he did three for 'Smells Like Teen Spirit' -- Vig did the verses with Cobain's voice alone, and then it sounds like he doubled them up for the pre-choruses and choruses.

Bonus? You can actually tell what the usually mush-mouthed Cobain is saying.

Listen to Isolated Audio of Kurt Cobain on 'Smells Like Teen Spirit'