Handwriting and other details have been reported based on the notes of David Berger, Andrew Homzy, Dr. Theodore Hudson, Walter van de Leur, Wayne Shirley and Dr. Mark Tucker.
There appears to be a number from the Duke Ellington Band Book: 22B.
6 parts and 1 score
Trees is contained in one folder consisting of 1 two page piano conductor score and 6 parts in Eb Major concert -- in ink -- in unidentified hand (Whaley?).
Piano conductor score does not indicate instrumentation. Parts for voices - soprano 1, soprano 2, alto, tenor, baritone, bass. Parts do not include lyrics. Parts are noted on the verso of parts for "Summertime," Folder F, grouping ii. -- from the Duke Ellington Library.