change one's tune

tune (tjuːn)
—n
1.	a melody, esp one for which harmony is not essential
2.	the most important part in a musical texture: the cello has the tune at that point
3.	the condition of producing accurately pitched notes, intervals, etc (esp in the phrases in tune, out of tune): he can't sing in tune
4.	accurate correspondence of pitch and intonation between instruments (esp in the phrases in tune, out of tune): the violin is not in tune with the piano
5.	the correct adjustment of a radio, television, or some other electronic circuit with respect to the required frequency (esp in the phrases in tune, out of tune)
6.	a frame of mind; disposition or mood
7.	obsolete a musical sound; note
8.	call the tune to be in control of the proceedings
9.	change one's tune, sing another tune, sing another a different tune to alter one's attitude or tone of speech
10.	informal to the tune of to the amount or extent of: costs to the tune of a hundred pounds
—vb (often foll by up)
11.	to adjust (a musical instrument or a changeable part of one) to a certain pitch
12.	to adjust (a note, etc) so as to bring it into harmony or concord
13.	(tr) to adapt or adjust (oneself); attune: to tune oneself to a slower life
14.	to make fine adjustments to (an engine, machine, etc) to obtain optimum performance
15.	electronics to adjust (one or more circuits) for resonance at a desired frequency
16.	obsolete to utter (something) musically or in the form of a melody; sing
17.	slang (South African) tune someone grief to annoy or harass someone
[C14: variant of tone]

tune

phrase tune in in reference to radio (later also TV) is recorded from 1913; figurative sense of "become aware" is recorded from 1926. Tune out "to eliminate radio reception" is recorded from 1908; fig. sense of "disregard, stop heeding" is from 1928. Tunesmith is a U.S. colloquial coinage first recorded 1926.

tune

vt. [from automotive or musical usage] To optimize a program or system for a particular environment, esp. by adjusting numerical parameters designed as hooks for tuning, e.g., by changing `#define' lines in C. One may `tune for time' (fastest execution), `tune for space' (least memory use), or `tune for configuration' (most efficient use of hardware). See bum, hot spot, hand-hacking.

change one's tune

Also, sing another or a different tune. Reverse one's views or behavior, switch sides, as in When she realized she was talking to the bank president, she quickly changed her tune, or I bet Dan will sing a different tune when he finds out what the salary is. A version of this term, sing another song, dates from about 1300, and it has been theorized that it alludes to itinerant minstrels who changed the words of their songs to please their current audience. The first locution was already in use by 1600. Also see dance to another tune.