Chet plays with a thumbpick and three fingers. You can play most of these tunes without a thumbpick and still get a good result, but you won't get Chet's tone and rhythmic drive. Some of Chet's moves can be adapted to a "flat-pick-and-two-fingers technique, but overall, you'll get the best results playing fingerstyle all the way.
The right-hand fingering is shown by the letters p, i, m, and a, where p stands for thumb, i for index, m for middle. and a for ring
In "Chinatown, My Chinatown." (section B. page 12), the thumb plays the stem-down notes to produce an alternating, bass accompaniment pattern. The stem-up melody-notes are played with i, m, and an occasional a. Chet uses a similar alternating bass pattern in "Blue Echo," "Lover Come Back." "Oh By lingo," "Trambone" and "Wobegon."