Metallica's "Enter Sandman" is the biggest metal song in existence. For many headbangers, the song has served as the gateway to heavy metal both when it was released in 1991 and through today.

What this 'Black Album' track did was strip away Metallica's more abrasive thrash moments in favor of a digestible mid-tempo romp. This signaled a change in the heavy music climate for years to come and gave the band an even bigger commercial breakthrough that afforded them the ability to stay relevant on and top despite grunge essentially nuking '80s metal.

The main riff to "Enter Sandman" was conceived by Kirk Hammett and James Hetfield originally had much darker lyrics set to the track, which were re-written until settling on the final version, as seen below.

Read the lyrics to the "Enter Sandman" below.

Say your prayers little one
Don't forget my son
To include everyone

I tuck you in, warm within
Keep you free from sin
'Til the sandman he comes

Sleep with one eye open
Gripping your pillow tight

Exit light
Enter night
Take my hand
We're off to never-never land

Something's wrong, shut the light
Heavy thoughts tonight
And they aren't of Snow White

Dreams of war, dreams of liars
Dreams of dragon's fire
And of things that will bite, yeah

Sleep with one eye open
Gripping your pillow tight

Exit light
Enter night
Take my hand
We're off to never-never land

Now I lay me down to sleep
(Now I lay me down to sleep)
Pray the lord my soul to keep
(Pray the lord my soul to keep)
If I die before I wake
(If I die before I wake)
Pray the lord my soul to take
(Pray the lord my soul to take)

Hush little baby don't say a word
And never mind that noise you heard
It's just the beasts under your bed
In your closet in your head

Exit light
Enter night
Grain of sand

Exit light
Enter night
Take my hand
We're off to never-never land

Boo! Yeah yeah!

We're off to never-never land
Take my hand
We're off to never-never land
Take my hand

We're off to never-never land
We're off to never-never land
We're off to never-never land

As of 2012, Metallica's 1991 self-titled album has been certified 16 times platinum by the RIAA.

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