This article discusses the place that the concept of rhythm occupies within Gilles Deleuze’s phi- losophy. I present a panorama of different ways to conceptualize thought throughout Deleuze’s writings from 1960’s to 1990’s, emphasizing the discussion about the threshold of thought. In the writings in partnership with Félix Guattari, Deleuze understand thought as an act of confronting chaos, what makes the problem of consistency a point of extreme relevance within his philosophical system. In this framework, the concept of thought is (...) described as a tension between consistency and infinite speed (chaos). In order to elaborate this concept of thought, Deleuze resumes his con- ceptualization of the three syntheses of the time and formulates with Guattari the concept of re- frain. I will show that the refrain is at the axis of an epistemological shift in the whole program of transcendental philosophy, by affirming a necessarily heterogeneous and aberrant Time, which features the concept of rhythm as the genetic element of difference. Within this conceptual frame- work, I follow the authors’ suggestion that the logic of schizoanalysis is analogous to the logic of subtractive sound synthesis. The main goal is to demonstrate that rhythm is at the core of Deleu- zian concept of difference and sound is at the core of Deleuzian concept of thought. (shrink)