Metallica learned more about playing with harmony and to use different styles during a song. "Orion" with its changings from speed to slowly parts is probably the best example for their new improved technique of song writing.

Album:
Master of Puppets

Why it was named Orion:
To Metallica the middle part of the song sounded a kind of spacey and starry so they named the song after the star constellation Orion.

The cover:
Korn covered "Orion" a few times for their live show.

Tribute to Cliff:
The song "Orion" was the music Metallica had chosen for Cliff's funeral on October 7th, 1986. Services were held in his hometown of Castro Valley. He was cremated, and his ashes were spread at the Maxwell Ranch.