Mr. Ikeda’s composition juxtaposed precision and imprecision: 440Hz is the current tuning standard for A, but that wasn’t always the case. Each car here was paired with a historical tuning, with frequencies ranging from 376.3Hz to 506.9Hz. Also, though this composition could have been performed cleanly by computer, it instead relied on amateur performers — the drivers, who in many cases were the creative and technical architects of their cars, but in this case were also the musicians. Each had a pocket-size synthesizer programmed to one specific frequency and a dedicated score instructing him or her how to manipulate the knobs at various points in the 27-minute piece.