Mechanical resonance Mechanical resonance Mechanical resonance is the tendency of a mechanical system to respond at greater amplitude when the frequency of its oscillations matches the system's natural frequency of vibration (its "resonance frequency" or "resonant frequency") than it does at other frequencies. It may cause violent swaying motions and even catastrophic failure in improperly constructed structures including bridges, buildings and airplanes. This is a phenomenon known as resonance disaster. Avoiding resonance disasters is a major concern in every building, tower and bridge construction project. The Taipei 101 building relies on a 660-ton pendulum—a tuned mass damper—to modify the response at resonance.
Some Girls Are Bigger Than Others performed live only once: at the final concert by the Smiths, at Brixton Academy, London, on 12 December 1986. The performance, which included a verse ("On the shop floor, there's a calendar, as obvious as snow, as if we didn't know") not used in the studio version, was recorded and later featured as a B-side on the 12" and cassette edition of the "I Started Something I Couldn't Finish" single in November 1987. Amateur footage of the entire concert has since appeared online. In Germany, "Some Girls Are Bigger Than Others" was released as a single in slightly edited form,