I've always been into really hard riffs. Not just hard as in heavy sounding, but hard as in difficult to play. I always like to challenge myself as much as I can. To me, the more obstacles you can overcome in your playing, the better guitar player you will be. Not to mention, I don't want some young whipper snapper to come along and cut my head off; but I know it's inevitable. One of the most challenging techniques that I'm still trying to master to this day, is double picking notes. Imagine playing 16th notes in an alternate picking pattern ( down up down up ) you hit the first note twice (down up) and you hit the second note twice again (down up). It gives your riff a "sense of urgency" to it; almost like a feeling of being chased. To better understand, I'll have to give you some examples. I believe one of the earliest uses of this technique (but I could be wrong) was Randy Rhoads in "I Don't Know" from Ozzy Osbourne's Blizzard Of Oz.
This is the Pre-Chorus. Notice on the second measure he plays 8th notes and when he gets to the fifth measure, he kicks it up a notch and plays 16th notes When he's playing the 16th notes, he's playing pretty much the same thing he played in the second measure; except certain notes are getting doubled. If you're not paying attention to this part, you'll probably miss it because it happens so fast. Bust out that Blizzard CD and you'll see what I mean.
There are some guitarists that take double picking to the stratosphere and make it difficult for the rest of us to follow along. Michael Romeo from Symphony X is one who comes to mind. Symphony X is kind of like Rising Force meets Dream Theater. Romeo is an absolute monster on the strings. Go to www.youtube.com and type his name in the search box to see for yourself; if you're into that type of thing. This example is from a song called "Orion The Hunter" from Twilight in Olympus.
Like I said, this guy is a monster; I'm sure he can play it in his sleep. For us normal people, it's very difficult to play these passages clean and precise so you've got to start off slow then build it up to the tempo of the song. I get better results when I hold the plectrum parallel to the string and pick the notes that way. It may take a while until you can play this with ease, but once you get it down it will be worth all the effort.
Last but not least, this is something I came up with from all these double picking riffs. I can play this only if I wash dishes for 20 minutes in scalding hot water to loosen up my hands and wrists (just kidding; but not really). I wrote this on a program called Powertab. Sometimes when I'm in a rut and can't come up with anything, I just start messing around with this program and something usually happens. I may not always be able to play it right then and there, but I mess around with it on the guitar until I'm able to. This was one of those times when I wanted to write a double picking riff but couldn't come up with anything. This is mostly based on power chords (D5, D#5, F5, C5, A#5).
I'm not too sure what key this is in, you might have to ask Anthony about that one. A lot of the times I find my wrist tensing up because I'm trying so hard to make these notes sound clean and fast. However, you've got to relax your hold on the plectrum and keep your wrist loose to nail it down otherwise it's going to sound like slop.
Like I said before, Randy Rhoads may or may not have been the first guitarist to start using this technique, but he most certainly wasn't the last. You might want to check out the Chorus Riff to Dream Theater's "Under A Glass Moon" from their Images and Words CD, the pre-chorus riff to Ozzy's Bark at the Moon, the main riff to Impellitteri's "Perfect Crime" from his System X CD, the main riff to Paul Gilbert's "I Feel Love" on his Burning Organ CD...the list goes on and on. I draw inspiration from all these guys and maybe you can, too.
Hopefully this will add a little something to your riffing since it seems that the "shred" is coming back. All these new main stream bands are starting to play guitar solo's in their songs...Imagine that! So I better get on the ball and start practicing...see you next time!