Among the many contributions to world music that have been cultivated in Cuba, one of the most important and influential styles is guaguancó. Guaguancó is one of three early forms of rumba: a folkloric performance art comprising music for percussion and voice accompanied by dance. The guaguancó is the youngest of the three remaining early rumba styles. A typical guaguancó performance features a percussion ensemble, lead singer, chorus, and two dancers. The percussion ensemble utilizes three conga drums and auxiliary instruments such as claves, a bamboo log struck with sticks, and various types of shakers. The three congas are tuned to high, medium, and low pitches and are each played by a separate drummer. The auxiliary instruments, along with the low and medium pitched congas, are used to repeat complementary patterns that establish rhythmic drive. The patterns played on the low and medium pitched congas combine to produce a tonal melody that is distinctive to the guaguancó style. The high-pitched conga, also called the quinto, is used to play improvisatory figures over the top of the ensemble. It is the improvisation played on the quinto that is one of the most important elements of a guaguancó performance. In Cuba, quinto drum improvisation is rarely taught. It is a practice learned by observing master drummers and being immersed in the rumba lifestyle. For percussionists outside of the rumba tradition, there are few resources available for mastering the art of quinto performance. The goal of this research is to show that percussionists can create quinto drum improvisations that are stylistically similar to those performed by rumberos by analyzing and assimilating the repeated rhythmic cells that permeate the repertoire. Presented in this document are transcriptions of several recorded rumba performances and analyses that reveal improvisational trends. It is shown that quinto performances are not purely spontaneous, but contain recurring rhythmic cells that are characteristic of guaguancó. Cataloguing these cells serves to establish a vocabulary of rhythms that can be threaded together to create stylistically appropriate improvisations. Examined in this research are performances by Los Muñequitos de Matanzas, Afrocuba de Matanzas, Columbia del Puerto de Cardenas, and percussionist Maximino Duquesne Martinez. History and development of Cuban rumba is discussed at length, along with practice suggestions and applications for improvising in salsa music. With annotated transcriptions in the form of three complete scores and seven quinto performances, this resource will assist musicians in understanding the governing principles of rhythmic improvisation in Cuban music.