This REAPER session is a companion artefact for The B-Format as Score:Composition, Interpretation, and Spatial Form in Ambisonics (JohannesSchütt, 2026), submitted to the Journal of Artistic Research (JAR) viathe Research Catalogue platform. What this session demonstrates: JAR_M3_SetA reproduces the Set A experiment discussed in §4.6 ofthe paper. Six decodings of the same 52-second B-format passage("Rethinking Thought", HOA-7, 64 channels, 48 kHz / 24 bit ambiX) arerendered side by side as a reduction gradient: A1 — full binaural reference (IEM BinauralDecoder, KU100 HRTF) A2 — 17-channel Geithain re-encode → SPS → binaural A3 — 8-channel octagon ring → GRM Tools → stereo A4 — ITU 5.1 → binaural A5 — stereo ±30° (two speakers only) A6 — omnidirectional W-channel alone All six are normalised to −23 LUFS (EBU R128). The audible differencebetween A1 and A6 is the spatial notation the B-format encodes — theempirical core of the paper's Thesis 2 (decoding as aestheticinterpretation, not neutral transmission). Contents: JAR_M3_SetA.rpp — REAPER project Media/ — source audio (64-channel HOA master, A00 Rethinking trought B-Format 64ch.wav) Renders/ — six stereo WAV renders referenced in the paper (A1–A6) Data/ — render manifest, post-render analysis script, BWF / meta-JSON per render, B-format directional-energy analysis docs/ — listening guide (DE), comparative analysis, B-format analysis report README.md — reproduction instructions, known-issue notes, integrity hashes Requires: The JAR Reaper Ambisonics Bundle(doi:10.5281/zenodo.19633159)for the REAPER environment, plug-ins, and render templates. Installthe bundle first, then open this session's RPP inside it. Target platform: Apple Silicon macOS 13+ (Ventura, Sonoma, Sequoia).Tested on REAPER v7.69 / IEM v1.15.0 / SPARTA v1.8.2 under the v1.0.0Bundle. License: CC BY 4.0 for session RPP, documentation, data, sourceaudio (Johannes Schütt's own work), and renders. Integrity: See the ZIP's README.md §5 for SHA-256 and MD5 hashes.