What is "to change one's tune"

Change \Change\ (ch[=a]nj), v. t. [imp. & p. p. Changed (ch[=a]njd); p. pr. & vb. n. Changing.] [F. changer, fr. LL. cambiare, to exchange, barter, L. cambire. Cf. Cambial.]

1. To alter; to make different; to cause to pass from one state to another; as, to change the position, character, or appearance of a thing; to change the countenance.

   Therefore will I change their glory into shame.
   --Hosea. iv. 7.

2. To alter by substituting something else for, or by giving up for something else; as, to change the clothes; to change one's occupation; to change one's intention.

   They that do change old love for new, Pray gods, they change for worse!
   --Peele.

3. To give and take reciprocally; to exchange; -- followed by with; as, to change place, or hats, or money, with another.

   Look upon those thousands with whom thou wouldst not, for any interest, change thy fortune and condition.
   --Jer. Taylor.

4. Specifically: To give, or receive, smaller denominations of money (technically called change) for; as, to change a gold coin or a bank bill.

   He pulled out a thirty-pound note and bid me change it.
   --Goldsmith.

   To change a horse, or To change hand (Man.), to turn or bear the horse's head from one hand to the other, from the left to right, or from the right to the left.

   To change hands, to change owners.

   To change one's tune, to become less confident or boastful.

   To change step, to take a break in the regular succession of steps, in marching or walking, as by bringing the hollow of one foot against the heel of the other, and then stepping off with the foot which is in advance.

   Syn: To alter; vary; deviate; substitute; innovate; diversify; shift; veer; turn. See Alter.