This paper explores the intricate relationship between unity, totality, and the musical idea in Arnold Schoenberg's compositional philosophy, situating these concepts within a broader theological framework. Schoenberg's writings emphasize that the 'totality' or 'whole' of a musical piece is synonymous with its core idea, arguing that true compositional unity arises only through the proper presentation of this idea. In Schoenberg's view, every compositional technique must serve the expression of the creator's idea, with the parts of a composition ultimately subjugated to the whole. This approach establishes a platform for dissecting unity within musical space, prompting a critical examination of how unity is conceived and achieved in music. The paper then extends this analysis by engaging with contemporary musicology and constructive theology, comparing Schoenberg's model of musical space with that of theologians Colin Gunton and Jeremy Begbie. While Schoenberg's conception is rooted in the metaphysical dimensions of the musical idea, Gunton and Begbie's models draw from trinitarian theology, specifically the concept of perichoresis—the dynamic, non-competitive, and mutually constitutive interrelational space of God's being. Through this comparison, the paper highlights how each thinker regards music as a fundamentally relational space, yet their respective philosophies/theologies of unity diverge significantly. Schoenberg's unity is hierarchical and totalizing, whereas Gunton and Begbie's are dynamic, mutually animating, and mutually constitutive. By placing Schoenberg's philosophy in dialogue with trinitarian thought, the paper aims to critique and reconstruct the notion of unity in musical space, demonstrating how theology can enrich musicological discourse and vice versa. Ultimately, this interdisciplinary approach seeks to foster new ways of understanding unity, benefiting both the philosophy of music and constructive theology.