Literature of “Waiting” (Entezar) is one of the motives which was considered by poets and literary critiques especially in early sixties but the approach of critiques to it has been mainly journalistic and not academic. Hence, there is space for academic and scientific researches. For studying such genre, it is valuable to explore and investigate it from different perspectives. The main questions of this article are how the musical function of this kind of poetry works and how this function and the theme of the poem are related. Accordingly, the authors analyze statistically ninety poems of this genre written by twenty great poets to find out the answers of these questions. In analyzing external music of waiting poetry, functions of rhythm in this kind of poetry, harmony between rhythm and theme, rising and falling rhythms, and transparent and opaque rhythms are investigated. Then, investigating marginal music of waiting poetry, the function of rhyme and its relation with the theme of waiting, the word rhyme and its musical link with other words of the verse, rhetorical and spiritual rhymes in this kind of poetry and dynamic and static radifs and their relation with the theme are all studied. Finally, internal music of waiting poetry and repetition and music in the titles of this poetry are explored. One of the results and findings of this article is that the poet of waiting poems unconsciously establishes a deep link between the sad concept of waiting and the form of such poems at the moment of composition.