The jazz classic Snake Rag was composed by King Joe Oliver and, according to some sources, the New Orleans bandleader Armand Piron. In 1923, King Oliver's Creole Jazz Band, with Louis Armstrong on second cornet and Johnny Dodds on clarinet, recorded it twice. To this day, those recordings - much re-issued - are treasured by enthusiasts of early New Orleans ensemble-style jazz.
I spent some time working out Snake Rag for myself and learning it. I made a lead-sheet for storage in my mini-filofaxes.
While doing this, I couldn't help noticing how easy the chord structure can be (if the pianist or banjo-player chooses to keep it simple and avoid subtleties). But the melody is busy, including those famous cascading chromatic runs.
The early jazz rags usually show signs of classical influence. There are several themes and a change of key. So it is with Snake Rag.
The tune's structure is:-
Introduction in Eb : 8 bars ending with the cascade.
Theme A : Usually played twice. 16 bars in Eb, again with the cascade at the end.
Theme B : Usually played twice. 16 bars, still in Eb. There is a 'break' (conventionally taken by the trombone) in bars 7 and 8; and the cascade at the end.
Next, Theme A is usually repeated (once).
Now, before I get to Theme C, here's the point I'm making about the chords: it is possible to play the entire tune so far while using only two chords - Bb7 and Eb. That is a very unusual feature.
Theme C (the final theme, normally played at least three times to allow for ensembles and solo improvisations) is in the new key. It is played in Ab.
It comprises 32 simple bars, requiring only four chords to cover them (Ab, Eb7, F7, Bb7). Again, how unusual!
The 32 bars divide conveniently into two very similar 16s, with the opportunity for a 'break' on bars 15 and 16. (The ways in which Armstrong and Oliver played these breaks have become legendary.)
To sum up, Snake Rag is to this day considered one of the most enjoyable and exciting jazz tunes from the early Twentieth-Century repertoire. Many bands still play it in their own fashion, but always keeping fairly closely to the structure I have outlined. Audiences love it and it sounds tricky, but in fact it is not too difficult to play - especially if you are in the chord-providing department of the band.