Today's guitar lick is a melodic based lick that is inspired by early musical interludes Metallica would frequently use in longer ballads. I've given this a bit a of a Celtic twist too. For excellent examples from the masters themselves I recommend "Fade to Black" from the great "Ride the Lightning" album. Frequently when Metallica use this type of melodic passage Kirk and James will play harmonized lines that give a fuller, richer sound to the overall composition. On studio recordings it is common to layer and harmonize several guitars for an almost orchestral sound.
