hahaha, I think if this guy wants to learn to sweep, he should just start doing it. You don't have to learn chords FIRST. Sweep arpeggios can be a great way to learn about chords. I mean, if that's what he's interested in, then that's the avenue that should be exploited. There is no "correct order" to learn things. If you want to learn sweeps first, just start sweeping.
My first exposure to sweep-picking was the solo in Rage Against the Machine's "Settle For Nothing." This is a great introduction to sweeping, because you don't actually fret any notes. You just rake the pick across muted strings.
The principle is simple enough: One note per string, as you go up, use one big downstroke. As you go down, use one big upstroke. Voila. Sweep-picking. The devil is in the details.
I would suggest you start off with something like this:
------------------
--------12---15--
------X----------
----X------------
--X--------------
------------------
What you've got there is something to just get you USED to sweeping. Just mute the strings and don't worry about specific notes so much, except for that B on the 12th fret. Use your index finger for all the muted strings and the B. Steve Vai does this all the time, and he got it from Frank Zappa, who got it from the old blues guitarists of the 50s.... it's not a pure sweep arpeggio, but it is a sweep. What you get is sort of a "tick-tick-tick-DING!" It sounds cool, and it gets you used to the general idea.
Okay. Got that down pat? Now let's try something similar that involves an actual sweep arpeggio:
--------------12h15p12-15^--
----------12------------------
------12----------------------
--14--------------------------
------------------------------
------------------------------
This shape outlines the top part of an Emin barre chord, but you can also look at it from the perspective of the E minor pentatonic scale or the E blues scale. Use your ring finger for the E on the 14th fret (the first note), and your index finger for all the notes on the 12th fret. This is a very basic and very common sweep arpeggio, and it's a great way to sound like you're playing a million notes, even though you're doing something that only takes a couple of hours to practice and nail. hahaha.
NOW FOR THE ADVANCED LESSON:
The advanced lesson is very simple. YOU CAN DO THIS WITH ANY CONFIGURATION OF STRINGS AND FRETS. If you can THINK IT UP, you can play it. That's sweep-picking in a nutshell. Granted, chords sound the best, and it's best to know which chords sound good together in the context of a song. For that, you'll need to study up on your harmonic theory, or just listen carefully to what sounds good TO YOU, and repeat.
There's no big secret. It's just up and down, one note per string. Muted strings or fretted strings, or open strings. It's all fair game!
Have fun, and practice hard!
