The question of identity in music composition is interrelated with the condition of musical material and form and the qualities which make musical ideas traceable. The mechanisms for creating musical identity during much of the modern period were based on the elements of pitch, rhythm, harmony and form. Until the twentieth century musical identities were regulated according to traditional systems. The advent of modernism in music was marked by the new solid identities, timbre and texture to the foreground as significant identity-bearing musical elements, and at the same time saw blurring of the traditional concepts of identity. The avant-garde movements of the post-World-War-II period in particular challenged the established identity concepts by liquefying the very essence of the musical work. The modern conceptual tools need to be replaced with new ones in order to address the current state of precariousness of musical material and form. In my original composition for sinfonietta entitled rh, I propose liquid identity as a new concept of musical identity. Liquid identity is based on a new image of musical sound which embodies the internal difference of sound in a self-existing conceptual model. In a state of liquidity all hierarchies flatten and the concept of development is rendered obsolete. The composer then writes constantly “in the middle” and compositional decisions are taken here and now. Consequently, the process of composition becomes a creative anarchic praxis without an end goal.