Armstrong uses a pick to play these arpeggios live, though many acoustic players execute it using hybrid picking or thumb-and-fingers. For the purest studio recreation, hold a standard medium plectrum (0.73mm to 0.88mm) and pick down on the bass strings while executing upward or alternate strokes across the treble strings.
Here is the exact acoustic fingerpicking pattern transcribed measure by measure:
<pre>[Intro / Verse Pattern]
G Gmaj7/F# Em7 G/D
e|-------3---------|-------3---------|-------3---------|-------3---------|
B|---3-----3---3---|---3-----3---3---|---3-----3---3---|---3-----3---3---|
G|-----0-----0---0-|-----0-----0---0-|-----0-----0---0-|-----0-----0---0-|
D|-----------------|-----------------|-----------------|-0---------------|
A|-----------------|-----------------|-----------------|-----------------|
E|-3---------------|-2---------------|-0---------------|-----------------|
C Cm G D/F#
e|-------3---------|-------3---------|-------3---------|-------2---------|
B|---3-----3---3---|---4-----4---4---|---3-----3---3---|---3-----3---3---|
G|-----0-----0---0-|-----5-----5---5-|-----0-----0---0-|-----2-----2---2-|
D|-----------------|-----------------|-----------------|-----------------|
A|-3---------------|-3---------------|-----------------|-----------------|
E|-----------------|-----------------|-3---------------|-2---------------|</pre>
Keep your fretting wrist relaxed. A common trap is clamping down on the neck, which inevitably deadens the open G and B strings. Ensure your thumb rests comfortably near the center back of the neck so your fingers arch naturally over the fretboard.
