Just read this today. Can it be true?

"Model T fords used a magneto ignition system. Part of getting it to work right was setting the gap on a set of points for each individual cylinder. The engine would rotated until that cylinder was engaged, and there would be a periodic spark discharge across the gap. The gap was set by adjusting it until it buzzed at a 'C' pitch, and a tuning fork was included in the tool kit that came with the car. Hence the origin of the term 'tuning up' the engine."