There are a many ways to compare these amazing diverse versions of Coo Coo. In all of the recordings, the banjo’s tuning is (mostly) the same: Sawmill (meaning gDGCD, or a transposition of those intervals). So, even though the tunes share a common tuning and the actual number of notes played are quite limited, the ways in which the performer strikes those strings can be vastly different. One way to compare the tunes is to (painstakingly I might add) count every time a note is played to determine which strings, or notes are the most important. This approach would perhaps give some insight into what makes one performer sound different from another. In other words, each performer has different “go to” licks that they perform and each of these licks or riffs has a particular sound.
Observe how each version of Coo Coo / Cuckoo Bird has a different incidence of note repetition. For example, in John Snipes’ version he plays each note close to the same number of times. This contrasts with Rufus Kasey’s version, where he emphasizes G and Bb and the other notes just pop in on occasion.