There are lots of interpretations for the opening phrase, but we could think of it as the B blues scale (B D E F F# A). It creates a great melodic variation over the Am backing. Guthrie also squeezes squeezes in a little lit tle B major triad on tthe he 3rd and 4th beats of measure 4, creating a cool outside moment.
5/4 LICK 15
As recorded by jamtrackcentral.com (From the 2015 Album 20 ODD-TIME LICKS: 5/4)
P V V V V V V V V V V V eV fV V g V f V g V V 5 j k V V V gV fV V PR V V I 4 M O e V f V e V V g V V g V V e V f V e V I V V V V V gV V V V V PR V V V V V V V V V V M = 132