Work on Felt (Variation 1) occupies a compelling threshold between sculpture and instrument, refusing to settle comfortably into either category. Naama Tsabar has stretched a large panel of raw industrial felt, 152 by 274 centimeters, across a wooden support and embedded within it the components of a functional stringed instrument: carbon fiber reinforcement, a piano string, a guitar tuning peg, and a piezo microphone connected to an amplifier. The felt, a material associated with absorption, softness, and acoustic dampening, becomes the body of something that produces sound rather than suppresses it. This contradiction is central to the work's conceptual logic, and it announces itself immediately in the object's spare, commanding presence. What distinguishes Work on Felt from conventional wall-based sculpture is its invitation to physical participation. The piano string can be plucked and its tension adjusted through the tuning peg, and as that tension changes, the felt panel itself responds, bowing forward or flattening against the wall. Form and pitch are inseparable here. A tighter string produces a higher note and a more pronounced arc in the surface; a looser string relaxes the panel and lowers the tone. The sculpture's appearance is therefore never fixed. Its visual character at any given moment is a record of sonic decisions made by those who have touched it. Tsabar developed the Work on Felt series beginning in 2012 as an ongoing investigation into materiality, participation, and the latent energy held within objects. This variation represents an early and foundational statement within that body of work, made at a moment when the series was establishing its formal and philosophical parameters. For collectors, it offers both a striking object and an active system, a work that continues to perform long after it leaves the exhibition context.