guitar_tap

Guitar Tap is a desktop application for luthiers and guitar builders that turns a simple tap on an instrument, a tonewood plate or a brace into measurable acoustic data. It captures the short ring-out after the tap, runs a high-resolution FFT, and displays the resonant peaks and material properties that matter when planning bracing, mass distribution and plate thickness. The measurement approach follows the tap-tone methodology described in Contemporary Acoustic Guitar Design and Build by Trevor Gore with Gerard Gilet, with the stated aim of improving reproducibility in guitar building. The project is free and open source, written in Python 3 with PySide6, and runs on Windows, macOS and Linux. Prebuilt installers for macOS and Windows are offered on the releases page; the macOS installer requires a system newer than Big Sur (11.0). A native edition for iPhone, iPad and Mac is described as forthcoming on the App Store. Three measurement modes are provided. Guitar mode identifies key body resonances such as Air/Helmholtz, Top, Back and others, each labeled with frequency, pitch and Q factor, plus the tap-tone ratio. Plate mode measures a tonewood blank, reporting Young's modulus along and across the grain, speed of sound, specific modulus, radiation ratio, a quality grade and a Gore target thickness. Brace mode is a fast single-tap measurement of a brace strip's stiffness, speed of sound, specific modulus and quality. Additional capabilities include a real-time spectrum that freezes automatically when a tap is detected, multi-tap averaging, side-by-side comparison of saved measurements, saving measurements and exporting spectra, images and PDF reports, and microphone calibration support for measurement microphones. Running from source requires Python 3.14 or later, Git, and platform dependencies: PortAudio on macOS via Homebrew, portaudio19-dev and libxcb-cursor-dev on Debian/Ubuntu, and no extra system packages on Windows. Dependencies are declared in pyproject.toml, with run-only, developer (pytest, mypy, ruff, weasyprint) and packaging (PyInstaller) extras. The app launches with python -m guitar_tap. Installer builds use platform scripts: AppImage tooling on Linux, Inno Setup on Windows, and code signing/notarization with an Apple Developer ID on macOS. A soak script (Tooling/soak.sh) repeatedly runs the fast pytest suite to surface nondeterministic teardown or garbage-collection races; the README notes that a green soak is confidence rather than proof. On startup the app checks the repository's public releases for a newer version and shows a dismissible banner; the request sends no personal data, audio or measurements, runs at most once a day, and can be disabled in Settings. Full user documentation is hosted on the project website, while design and roadmap documents live in a separate project hub repository. The software is licensed under GPL-3.0, copyright Dolce Sfogato (David Smith).