Here is an alternate picking exercise for guitar based around the E and B strings using 16th notes. It is based on the C Major Scale but uses the high E string as a repeating pedal note so this idea could be expanded on over a chord progression using the E Phrygian Mode. In the video the lick is played at three speeds. It is a good idea to practice this slowly with a metronome and using strict alternate picking. Great examples of this kind of repeating pedal note are found in Iron Maiden's "Waster Years" and ACDC's "Thunderstuck".