A YouTube clip featuring late Nirvana frontman Kurt Cobain's isolated vocal track on 'Smells Like Teen Spirit' has become an Internet sensation over the past week -- two years after it was posted on the popular video-sharing website.

The 1991 release of Nirvana's 'Smells Like Teen Spirit' was a watershed moment in the history of rock music. The meteoric rise of that one song ushered in an entire new wave of bands that saved the then flat-lining genre. The massive single has been played millions of times and is still a staple at rock radio stations today, but fans are hearing the song in an entirely different way after an old YouTube clip got noticed by the interwebs last week.

Last week, a two-year-old YouTube clip featuring Kurt Cobain's unaccompanied vocal track on 'Smells Like Teen Spirit' made it to the front page of several major music websites after the clip was posted on blogger Bobby Ownski's The Big Picture. The haunting clip offers a new way to appreciate both Cobain's vocals and the subtle brilliance added to the equation by 'Nevermind' producer Butch Vig.

In a society where Rebecca Black's 'Friday' can become an overnight sensation via YouTube, it is somewhat criminal that this piece of rock history has gone largely unnoticed for two years. The 'Smells Like Teen Spirit' isolated vocal track is not the only one of Cobain's on the Web. There are several others, including 'Drain You,' 'Lounge Act' and 'You Know You're Right.' Check them out below:

Kurt Cobain's Isolated Vocal from 'Smells Like Teen Spirit'

Cobain's Isolated Vocal from 'Drain You'
Cobain's Isolated Vocal from 'Lounge Act'
Cobain's Isolated Vocal from 'You Know You're Right''