The term "blues" is conventionally used to refer to a state of sadness or melancholy, but to conclude from this that the musical genre of the same name is merely an expression of unrelieved sorrow is to miss its deeper meaning. Despite its frequent focus on such themes as suffering and self-pity, and despite the censure that it has sometimes received from church communities, the blues, understood more fully, actually has much in common with the traditional religious music known as spirituals. Each genre, in its own way, aims to bring about what could be called a spiritual transformation: spirituals produce a religious experience and the blues elicits an analogous response. In fact the blues has even been characterized as a form of "secular spiritual." The implication of this apparently contradictory terminology is clear: the blues shares an essential aspect of spirituals. Indeed, the blues and spirituals may well arise from a common reservoir of experience, tapping into an aesthetic that underlies many aspects of African American culture.

Critics have noted that African American folk tradition, in its earliest manifestations, does not sharply differentiate reality into sacred and secular strains or into irreconcilable dichotomies between good and evil, misery and joy. This is consistent with the apparently dual aspect of the blues and spirituals. Spirituals, like the blues, often express longing or sorrow, but these plaintive tones are indicative of neither genre's full scope: both aim at transforming their participants' spirits to elation and exaltation. In this regard, both musical forms may be linked to traditional African American culture in North America and to its ancestral cultures in West Africa, in whose traditional religions worshippers play an active role in invoking the divine—in creating the psychological conditions that are conducive to religious experience. These conditions are often referred to as "ecstasy," which is to be understood here with its etymological connotation of standing out from oneself, or rather from one's background psychological state and from one's centered concept of self.

Working in this tradition, blues songs serve to transcend negative experiences by invoking the negative so that it can be transformed through the virtuosity and ecstatic mastery of the performer. This process produces a double-edged irony that is often evident in blues lyrics themselves; consider, for example the lines "If the blues was money, I'd be a millionaire," in which the singer reconfigures the experience of sorrow into a paradoxical asset through a kind of boasting bravado. One critic has observed that the impulse behind the blues is the desire to keep painful experiences alive in the performer and audience not just for their own sake, but also in order to coax from these experiences a lyricism that is both tragic and comic.