The Kitāb al-Aghānī (the Book of Songs) is one of the most important sources for Arabic literature and history. While its compiler, Abū al-Faraj al-Iṣfahānī (died after 356/967), is generally viewed as a “Zaydī Shīʿī”, no study has engaged in depth with the manifestation of his sectarian perspective in the Aghānī. This thesis addresses the question of whether al-Iṣfahānī’s sectarian perspective can be discerned in the Aghānī via literary analysis based primarily upon redaction criticism. By examining the compiler’s interventions (which took place by means of selecting, repeating, and juxtaposing source material, as well as by his comments and editorial remarks), this thesis argues that al-Iṣfahānī indeed presents past people and events central to the Shīʿī worldview in accordance with his sectarian affiliation. Furthermore, this thesis questions the label “Zaydī” that has been attached to al-Iṣfahānī. Based on textual analyses of the Aghānī, as well as evidence from his Maqātil al-Ṭālibīyīn (“The Ṭālibid Martyrs”) and other evidence for the tenth-century context, this thesis suggests that al-Iṣfahānī’s religious thought can be construed as a “mild” form of Shīʿism ― in the sense that it does not entail belief in a specific lineage of imams and repudiation of most of the Companions including the first three caliphs ― but cannot necessarily be identified with any sect, as set down in the heresiography. It is also suggested that this kind of Shīʿism may have been promoted by al-Iṣfahānī’s patron, the Būyid vizier, Abū Muḥammad al-Muhallabī (291–352/903–963) in the complex sectarian context of mid-tenth century Iraq. This thesis comprises seven chapters. Chapters One and Two introduce the life of the compiler, the wider historical context, the Aghānī, its textual problems, and its overarching structure. These two chapters lead to three conclusions: first, the Aghānī, in all likelihood, was dedicated to Abū Muḥammad al-Muhallabī; second, the view that al-Iṣfahānī was a Zaydī is untenable; third, it is very likely that the Aghānī retains its original form (as designed by al-Iṣfahānī). Chapter Three investigates the sources used by al-Iṣfahānī in the Aghānī with regard to their transmission in order to establish that the published text can indeed be subjected to redaction criticism for the purpose of better understanding the compiler’s agenda (or agendas). Chapters Four and Five present the results of the literary analysis of the Aghānī, which demonstrate the articulation of a Shīʿī past in the Aghānī, as well as highlighting the limits of redaction criticism and al-Iṣfahānī’s other editorial concerns. Building upon Chapter Five, which concludes that the Aghānī reflects al-Iṣfahānī’s sectarian vision, Chapter Six characterizes al-Iṣfahānī’s Shīʿī beliefs by examining his treatment of Ghulāt, Imāmīs, Sunnīs, ʿAlids, and the Companions, including the first three caliphs. Chapter Seven puts the results of the analyses into their historical context, specifically in light of the career of his patron, al-Muhallabī. The Conclusion outlines the key findings of this thesis, with remarks on potential avenues for future research.