playing freight train is melody picking with fingers thumb uses basses basse, its easiest i find in c, yes i know libba cooten played upside down most people find it easiest to use conventionalpicking with index and middle playing melody
.the other way of picking with thumb is also easy in c and g ,
in c the melody falls through the chords, start with c 5 string3 fret then d open4 string, then e 4 string 2nd fret, then little finger let hand on 4 string 4 fret, then open3 string,then 3 string2nd fret then open 2 string,then 2 string first fretthen 2 string3rd fret little finger of left hand then open 1 string then first stringfirst fret then first string 3rd fret you have played an octave and a half of c majorscale cdefgabc defg.dovan talks about this style on you tube it isbased on the playing of maybelle carter, if you dont use a finger pick it is necessary to use hammering on and pulling off to get some half notes.
pfr, feel free to strum but AKE mentioned picking melody. playing in g is same pattern as c but one string lower