As you probably know, sweep picking is the technique of playing multiple notes with the same pick stroke. However, incorporating the rest stroke is the difference between a real sweep and a series of free strokes.
To make the most of the economic benefits of sweep picking, it’s important that when the pick leaves one string, it comes to rest on the next string immediately after, waiting for fretting hand to press down on the next note before leaving the string. Even before guitar picks were used, many nylon string players adopted this approach with their fingers and called it Apoyando (supporting stroke).
The sounding of the notes will be caused by the pick leaving the string rather than arriving at each new string. Let’s try that in the first example, muting the strings for now and focusing only on the picking hand.
To make the stepping process even smoother (and faster!), lean the pick forward into a downward pick slant (\ p.s.) when ascending, reversing it into an upward pick slant (/ p.s.) when descending. Doing so brings even more of that brushing sound to your sweeping.
With your rest stroke technique in place, let’s try a five-string A Minor triad. If you remove rest strokes and pick slants, suddenly the same pattern becomes slower and cumbersome.
When combining alternate and sweep picking, simply apply rest strokes to the sweep portions, and alternate pick as normal. In the next example, rest strokes occur between the D string and high E string. You can maintain the same downward pick slant throughout this extended A Minor triad.
To practise rest strokes through a chord progression, here’s an etude from my book Sweep Picking Speed Strategies for Guitar. This consists of two different shapes for the A Minor triad, a single shape moved around for each of the diminished triads, finishing with an E Major triad in bar four.
Remember that sweep picking is all about flow. If picking is staggered and disjointed, it can really take the sweep out of sweep picking. To adopt all of the essential rudiments, Chapter One of my new book has everything you need to get started in the business of flowing arpeggio lines.