The results are often slapdash, with spur-of-the-moment arrangements, and everyone hoping for the best.
Obviously, the band must have studied the original recording by Jelly Roll Morton's Red Hot Peppers in detail, because they follow it closely.
The structure goes like this:
Both bands start in the key of C.
Four bars 'running up the ladder'
Featuring guitar breaks and then the cornet
but with the break in bars 7 and 8 taken by the piano (Red Hot Peppers) and by the banjo (Tuba Skinny - not having a piano at the time)
THEME B second time
Clarinet leads throughout, including the break (Red Hot Peppers)
Clarinet leads but washboard takes the break (Tuba Skinny)
THEME B third time
Trombone and string bass alternate the lead (Red Hot Peppers)
Trombone and Tuba alternate the lead (Tuba Skinny)
Without any need for a signal, there is then a seamless transition into the key of F (occurring at 1 minute 41 seconds into the Tuba Skinny video).
Melody (a firm statement stabbing out the notes of the chords) played by the cornet
THEME C second time
Ensemble, featuring the clarinet on the flowing runs
THEME C third time
Taken as a piano solo (Red Hot Peppers) but as a Trombone solo (Tuba Skinny)
THEME C fourth time
Ensemble out-chorus (Red Hot Peppers)
Chorus led by Tuba (Tuba Skinny)
(The Red Hot Peppers version - under 3 minutes in total - ends at this point, but with a neat two-bar coda)
THEME C fifth time
Ensemble (Tuba Skinny - everyone swinging joyously)
THEME C sixth time
Ensemble (Tuba Skinny - again everyone swinging joyously). Simple end. No coda.
Note how nobody puts a foot wrong with the various two-bar breaks. Notice too how even Erika (whose main rôle is as vocalist) gets the bass drum beats exactly right - stopping at those moments when 'silent beats' are required. Notice how there is no need for signals from Shaye, though she gives the slightest indication (hardly required) at 2 minutes 35 seconds that Todd is leading the next chorus.
By the time when I videoed them playing the tune in Royal Street, New Orleans, three years later, (https://www.youtube.com/watch?v=IUICxSTjzPc), they had very slightly tweaked the arrangement, with minor alterations to the structures and playing of the breaks, for example. Have fun spotting the differences. They had added a Coda too.
Obviously, to get all that right, from memory, the members of the band have to put in plenty of hard work in the woodshed. Their dedication is an example to us all.