Louis Armstrong and His Hot Five
It was a typical New Orleans jazz band in instrumentation, consisting of trumpet, clarinet, and trombone backed by a rhythm section. The original New Orleans jazz style leaned heavily on collective improvisation, where the three horns together played the lead: the trumpet played the main melody, and the clarinet and trombone played improvised accompaniments to the melody. This tradition was continued in the Hot Five, but because of Armstrong's creative gifts as a trumpet player, solo passages where the trumpet played alone began to appear more frequently. In these brilliant solos, Armstrong laid down the basic vocabulary of jazz improvising, and became its founding and most influential exponent.
The Hot Five was a recording group organized at the suggestion of Richard M. Jones for Okeh Records. All their records were made in Okeh's Chicago, Illinois recording studio. The exact same personnel recorded a session made under the pseudonym "Lil's Hotshots" for Vocalion/Brunswick. While the musicians in the Hot Five played together in other contexts, as the Hot Five they were a recording studio band that performed live only for two parties organized by Okeh Records.
There were two different groups called "Louis Armstrong and his Hot Five", the first recording from 1925 through 1927 and the second in 1928; Armstrong was the only musician in both groups.
The first Hot Five 
The original Hot Five were, other than Armstrong's wife Lil Hardin Armstrong on piano, all New Orleans musicians who Armstrong had worked with in that city in the 1910s: Kid Ory on trombone, Johnny Dodds on clarinet, and Johnny St. Cyr on guitar and banjo.
On one session in December 1927, Lonnie Johnson was added on guitar.
The recordings of this group are considered by many to be uneven, with some of the blunders (e.g. the mis-timed hokum at the end of "Heebie Jeebies") becoming notorious in jazz circles, and the solos of Dodds, Ory and Hardin sounding distinctly pedestrian in comparison with Armstrong's. However, the ensemble passages are frequently effective, and the genius of Armstrong's cornet or trumpet playing touch virtually every recording. Some of the more important examples are "Cornet Chop Suey", "Muskrat Ramble", "Hotter Than That" and "Struttin' With Some Barbecue".
The 1928 Hot Five 
In 1928, Armstrong revamped the recording band, replacing everyone but himself with his band-members in the Carrol Dickerson Orchestra which Armstrong was playing with Fred Robinson, trombone, Jimmy Strong, clarinet and tenor saxophone, Earl Hines, piano, Mancy Carr (not "Cara" as has often been misprinted) on banjo, and Zutty Singleton on drums.
This second Hot Five played music that was specifically arranged as opposed to the more free-wheeling improvised passages in the earlier Hot Five structures. A tentative movement toward the kind of fully arranged horn sections that would dominate swing music a decade later was starting to become fashionable, and this second Armstrong group embraced a rudimentary version of it, with Don Redmon as arranger providing some written-out section parts. Jimmy Strong on clarinet and Fred Robinson on trombone were not as strong soloists as Dodds and Ory had been with the earlier band, but with pianist Earl Hines, Armstrong here met a musician who was more nearly his equal technically and creatively than any other in either band.
Thus, these sessions resulted in some of the most important masterpieces of early jazz, of which "West End Blues" is arguably the best known. Other important recordings include "Basin Street Blues", "Tight Like This", "Saint James Infirmary", and "Weather Bird". In the last named, only Armstrong and Hines are present, turning an old rag number into a tour-de-force of inspired musical runs as the trumpet and piano playfully come together, draw apart to compete, and come together again, over several cycles.
See also 
- Louis Armstrong and His Hot Seven
- Louis Armstrong Hot Five and Hot Seven Sessions
- Hot Fives & Sevens, a 2000 compilation album of music by the group