From The Collaborative International Dictionary of English v.0.48:
Tune \Tune\, v. t. [imp. & p. p. Tuned (t[=u]nd); p. pr. & vb. n. Tuning.] 1. To put into a state adapted to produce the proper sounds; to harmonize, to cause to be in tune; to correct the tone of; as, to tune a piano or a violin. " Tune your harps." --Dryden. [1913 Webster] [1913 Webster]
2. To give tone to; to attune; to adapt in style of music; to make harmonious. [1913 Webster]
For now to sorrow must I tune my song. --Milton. [1913 Webster]
3. To sing with melody or harmony. [1913 Webster]
Fountains, and ye, that warble, as ye flow, Melodious murmurs, warbling tune his praise. --Milton. [1913 Webster]
4. To put into a proper state or disposition. --Shak. [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Tuning \Tun"ing\ (t[=u]n"[i^]ng), a. & n. from Tune, v. [1913 Webster]
Tuning fork (Mus.), a steel instrument consisting of two prongs and a handle, which, being struck, gives a certain fixed tone. It is used for tuning instruments, or for ascertaining the pitch of tunes. [1913 Webster]