Guillén drew from his mixed African and Spanish ancestry and education to combine his knowledge of traditional literary form with firsthand experience of the speech, legends, songs, and songs of Afro-Cubans in his first volume of poetry, Motivos de son. It was soon acclaimed as a masterpiece and widely imitated. In the 1920s, when Afro-Cuban sounds and instruments were changing the world of Cuban music, Afro-Cuban culture began to be expressed in art and literature as well. Initially, Afro-Cuban poetry, or “negrista” poetry, was mainly published by European Cubans such as Emilio Ballagas, Alejo Carpentier, and José Tallet. It was not until the 1930s that Guillén would appeal in literary terms by expressing a personal account of the struggles, dreams, and mannerisms of Afro-Cubans.
Guillén became outspoken politically, and dissatisfied with picturesque portrayal of the daily life of the poor. He began to decry their oppression in his poetry volumes Sóngoro cosongo and West Indies Ltd. Guillen also wrote Cantos para soldados y sones para turistas, which reflected his growing political commitment. Guillén is probably the best-known representative of the “poesía negra” (“black poetry”), which tried to create a synthesis between black and white cultural elements, a “poetic mestizaje”. Characteristic for his poems is the use of onomatopoetic words (“Sóngoro Cosongo”, “Mayombe-bombe”) that try to imitate the sound of drums or the rhythm of the son. Silvestre Revueltas’s symphonic composition Sensemayá was based on Guillén’s poem of the same name, and became that composer’s second-best-known work, after the film score for La noche de los mayas.
Guillén later became acknowledged by many critics as the most influential of those Latin American poets who dealt with African themes and re-created African song and dance rhythms in literary form. Guillen made an international mark with the publication of Motivos de son (1930). The work was inspired by the living conditions of Afro-Cubans and the popular son music. The work consists of eight short poems using the everyday language of the Afro Cubans. The collection stood out in the literary world because it emphasized and established the importance of Afro-Cuban culture as a valid genre in Cuban literature.
In Man-Making Words: Selected Poems of Nicolás Guillén, Angel Aguier, in reference to Motivos de son, wrote that
“the ‘son,’ a passionate dance born of the Negro-white encounter under Caribbean skies in which the words and music of the people culminate in song, is the basic substance of the elemental poetry which Guillen intuitively felt as the expression of the Cuban spirit…. He specifically chose the son as the mixed artistic creation of the two races that make up the Cuban population; for the son, in form and content, runs the full gamut of every aspect of our national character.” 
This quote establishes how the son, such a profound musical genre of that time, initiated the fusion of black and white Cuban culture. Guillén’s incorporation of the genre into his writings, symbolized and created a pathway for the same cultural fusion in Cuban literature.
Guillén’s unique approach of using the son in his poetry is expressed in his book Sóngoro consongo (1931). In this work, Guillén included poems that depicted the lives of Cubans and emphasized the importance of Afro-Cuban culture in Cuban history. Sóngoro consongo captures the essence of the Afro-Cuban culture and ways that the people deal with their personal situations.
Guillén’s poem, “La canción del bongó”, from Sóngoro consongo, is a fusion of West African and Hispanic literary styles, contributing to his unique literary vision.