This is a fast 16th-note alternate picking run in C# minor that starts out on the high E string and moves across the neck, staying pretty much in the ninth through seventh positions and ending with a whole-step pull bend and vibrato on the low E string.
There’s a bit of a wide fret-hand stretch at the beginning, followed by more conventional, compact shapes as you descend across the strings. I’ve included my exact fret-hand fingerings to take the guesswork out of it for you.
I’ve also included my picking strokes to guide you. You’ll notice that the run is not 100 percent alternate picked, however, as I do pull off to two notes, one in bar 1 and one bar 2, but my pick hand stays in sync with the established pattern to keep the down-strokes falling on the downbeats.
As a result, there are two upstrokes in a row, before and after each pull-off. Take it slow and steady at first and gradually ramp-up the tempo while trying to keep your picking strokes relaxed and economical, with no wasted movement.
The run is based mostly on the C# Dorian mode [C# D# E F# G# A# B], which is the same set of notes as the B major scale [B C# D# E F# G# A#], but oriented around a C# minor tonal center. In bar 1 I add the flat five, G natural [G string, 12th fret], which is borrowed from the C# blues scale [C# E F# G G# B].
It’s worth noting here that the run doesn’t simply descend straight through either scale, but rather changes direction often and incorporates wide skips, which makes it more interesting to listen to and more fun to play.