Baroque and Early Jazz are two styles of music that one would not normally compare. With nearly 200 years separating them, the two styles' numerous similarities have been concealed due to a secular-sacred distinction. Dixieland or Early Jazz, originated from New Orleans in the early 20th Century. Born from mix of the preceding military, ragtime and blues styles, Jazz's purpose was primarily to provide entertainment in bars. Conversely, the Baroque Period spanned from 1600 to 1750. Composers worked chiefly to serve the regal and ecclesiastical authorities, producing music for dances and church services.

From the 1920's, with the help of Louis Armstrong, Jazz began to incorporate many baroque characteristics into its diverse and rhythmic compositions. This Baroque Revival can be clearly observed in a detailed examination of Mack the Knife and the Brandenberg Concertos. Despite such differences as contrasting instruments, addition of voice and contrasting level of formality; these two landmark compositions highlight the many parallels in melody, harmonic language, accompaniment and form.      

Differences between the two styles are easily distinguished. Where Baroque had its basis firmly in strings, Jazz drew upon mainly brass and woodwind instruments. In fact many of these Jazz instruments such as saxophone, clarinet and trombone were not even developed until many years after the Baroque era. Also, the ornamental and formal nature of Baroque music is vastly different from the laid back and more simplistic Jazz style. This contrast is partially due to the large difference is ensemble size: a Baroque orchestra being significantly larger than a Dixieland band.

Despite the difference in the number of musicians, the arrangement of instruments within both periods has many commonalities. Both styles employ the use of two distinct musical groups, one which features and another which acts as harmonic and rhythmic accompaniment. In the case of the Baroque period the two sections were the concertino, the small group of virtuosic soloists and the ripieno (the tutti orchestra). In Jazz, the soloist group was called the Front Line. This usually included the clarinet, trumpet and trombone. Jazz's ripieno equivalent was the aptly named Rhythm Section. This group included the drum kit, banjo, upright bass and piano. Both Baroque and Jazz styles frequently relied on a strict form for their compositions. In Mack the Knife there are five 32 bar choruses; each with the same melodic movement and in the first movement of the second Brandenberg Concerto, ritornello form is used. This structured form uses contrasting sections of virtuosic solos and chorus-like snippets played by the full orchestra.

Another similarity is the use of improvisation. Although not obvious, the concertino uses improvisation in the episodes of movements in ritornello form.  In the Brandenberg Concertos grace notes and ornaments were often used by the concertino and the harpsichord to perpetuate the sound and generate interest. A Dixieland band also uses improvisation, however instead of individual improvisation, Collective Improvisation was applied. This form was achievable due to their smaller size of 5 to 8 musicians. Often a whole chorus was dedicated to this form and was known as Dixieland Break. In both instances, this improvisation was able to occur in a cohesive manner due to the use of an outlined chord symbols. The chords indicated by the symbols are improvised on by the harpsichord in a baroque orchestra and the piano in a jazz band. The chord progression (notated in the Baroque period as Figured Bass) is repeated many times and directs the melody. Both Mack the Knife and the Brandenberg Concertos show evidence of this similarity.

Despite their many and vast disparities, the Baroque and Jazz styles (and in particular Mack the Knife and Bach's Brandenberg Concerto) share various and significant similarities. In particular it is the commonalities of melody, harmonic language, accompaniment and form which created what we now know as the Baroque Revival.