"adjustments made to an automobile to improve its working," 1911, from verbal phrase tune up "bring to a state of effectiveness," 1718, in reference to musical instruments, from tune (v.) + up (adv.). Attested from 1901 in reference to engines. Meaning "event that serves as practice for a later one" is from 1934, U.S. sports jargon.[tune-up etymology, tune-up origin, 英语词源]