Source : Webster's Revised Unabridged Dictionary (1913)

Tune \Tune\, v. t. [imp. & p. p. {Tuned}; 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.

Tune \Tune\, n. [A variant of tone.]
   1. A sound; a note; a tone. ``The tune of your voices.''
      --Shak.

   2. (Mus.)
      (a) A rhythmical, melodious, symmetrical series of tones
          for one voice or instrument, or for any number of
          voices or instruments in unison, or two or more such
          series forming parts in harmony; a melody; an air; as,
          a merry tune; a mournful tune; a slow tune; a psalm
          tune. See {Air}.
      (b) The state of giving the proper, sound or sounds; just
          intonation; harmonious accordance; pitch of the voice
          or an instrument; adjustment of the parts of an
          instrument so as to harmonize with itself or with
          others; as, the piano, or the organ, is not in tune.

                Like sweet bells jangled, out of tune and harsh.
                                                  --Shak.

   3. Order; harmony; concord; fit disposition, temper, or
      humor; right mood.

            A child will learn three times as much when he is in
            tune, as when he . . . is dragged unwillingly to
            [his task].                           --Locke.

Tune \Tune\, v. i.
   1. To form one sound to another; to form accordant musical
      sounds.

            Whilst tuning to the water's fall, The small birds
            sang to her.                          --Drayton.

   2. To utter inarticulate harmony with the voice; to sing
      without pronouncing words; to hum. [R.]

Source : WordNet®

tune
     n 1: a succession of notes forming a distinctive sequence; "she
          was humming an air from Beethoven" [syn: {melody}, {air},
           {strain}, {melodic line}, {line}, {melodic phrase}]
     2: the property of producing accurately a note of a given
        pitch; "he cannot sing in tune"; "the clarinet was out of
        tune"
     3: the adjustment of a radio receiver or other circuit to a
        required frequency

tune
     v 1: adjust for (better) functioning; "tune the engine" [syn: {tune
          up}]
     2: of musical instruments; "My piano needs to be tuned" [syn: {tune
        up}] [ant: {untune}]

Source : Free On-Line Dictionary of Computing

tune
     
         (From musical, possibly via automotive, usage) To
        {optimise} a program or system for a particular environment,
        especially 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}.
     
        [{Jargon File}]
     
        (1999-06-05)