The Collaborative International Dictionary of English v.0.48:

Pitch \Pitch\, n.
   1. A throw; a toss; a cast, as of something from the hand;
      as, a good pitch in quoits.
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   Pitch and toss, a game played by tossing up a coin, and
      calling "Heads or tails;" hence:

   To play pitch and toss with (anything), to be careless or
      trust to luck about it. "To play pitch and toss with the
      property of the country." --G. Eliot.

   Pitch farthing. See Chuck farthing, under 5th Chuck.
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   2. (Cricket) That point of the ground on which the ball
      pitches or lights when bowled.
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   3. A point or peak; the extreme point or degree of elevation
      or depression; hence, a limit or bound.
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            Driven headlong from the pitch of heaven, down
            Into this deep.                       --Milton.
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            Enterprises of great pitch and moment. --Shak.
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            To lowest pitch of abject fortune.    --Milton.
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            He lived when learning was at its highest pitch.
                                                  --Addison.
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            The exact pitch, or limits, where temperance ends.
                                                  --Sharp.
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   4. Height; stature. [Obs.] --Hudibras.
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   5. A descent; a fall; a thrusting down.
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   6. The point where a declivity begins; hence, the declivity
      itself; a descending slope; the degree or rate of descent
      or slope; slant; as, a steep pitch in the road; the pitch
      of a roof.
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   7. (Mus.) The relative acuteness or gravity of a tone,
      determined by the number of vibrations which produce it;
      the place of any tone upon a scale of high and low.
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   Note: Musical tones with reference to absolute pitch, are
         named after the first seven letters of the alphabet;
         with reference to relative pitch, in a series of tones
         called the scale, they are called one, two, three,
         four, five, six, seven, eight. Eight is also one of a
         new scale an octave higher, as one is eight of a scale
         an octave lower.
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   8. (Mining) The limit of ground set to a miner who receives a
      share of the ore taken out.
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   9. (Mech.)
      (a) The distance from center to center of any two adjacent
          teeth of gearing, measured on the pitch line; --
          called also circular pitch.
      (b) The length, measured along the axis, of a complete
          turn of the thread of a screw, or of the helical lines
          of the blades of a screw propeller.
      (c) The distance between the centers of holes, as of rivet
          holes in boiler plates.
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   10. (Elec.) The distance between symmetrically arranged or
       corresponding parts of an armature, measured along a
       line, called the pitch line, drawn around its length.
       Sometimes half of this distance is called the pitch.

   Concert pitch (Mus.), the standard of pitch used by
      orchestras, as in concerts, etc.

   Diametral pitch (Gearing), the distance which bears the
      same relation to the pitch proper, or circular pitch, that
      the diameter of a circle bears to its circumference; it is
      sometimes described by the number expressing the quotient
      obtained by dividing the number of teeth in a wheel by the
      diameter of its pitch circle in inches; as, 4 pitch, 8
      pitch, etc.

   Pitch chain, a chain, as one made of metallic plates,
      adapted for working with a sprocket wheel.

   Pitch line, or Pitch circle (Gearing), an ideal line, in
      a toothed gear or rack, bearing such a relation to a
      corresponding line in another gear, with which the former
      works, that the two lines will have a common velocity as
      in rolling contact; it usually cuts the teeth at about the
      middle of their height, and, in a circular gear, is a
      circle concentric with the axis of the gear; the line, or
      circle, on which the pitch of teeth is measured.

   Pitch of a roof (Arch.), the inclination or slope of the
      sides expressed by the height in parts of the span; as,
      one half pitch; whole pitch; or by the height in parts of
      the half span, especially among engineers; or by degrees,
      as a pitch of 30[deg], of 45[deg], etc.; or by the rise
      and run, that is, the ratio of the height to the half
      span; as, a pitch of six rise to ten run. Equilateral
      pitch is where the two sloping sides with the span form an
      equilateral triangle.

   Pitch of a plane (Carp.), the slant of the cutting iron.

   Pitch of poles (Elec.), the distance between a pair of
      poles of opposite sign.

   Pitch pipe, a wind instrument used by choristers in
      regulating the pitch of a tune.

   Pitch point (Gearing), the point of contact of the pitch
      lines of two gears, or of a rack and pinion, which work
      together.
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The Collaborative International Dictionary of English v.0.48:

Concert \Con"cert\ (k[o^]n"s[~e]rt), n. [F. concert, It.
   concerto, conserto, fr. concertare. See Concert, v. t.]
   1. Agreement in a design or plan; union formed by mutual
      communication of opinions and views; accordance in a
      scheme; harmony; simultaneous action.
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            All these discontents, how ruinous soever, have
            arisen from the want of a due communication and
            concert.                              --Swift.
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   2. Musical accordance or harmony; concord.
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            Let us in concert to the season sing. --Cowper.
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   3. A musical entertainment in which several voices or
      instruments take part.
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            Visit by night your lady's chamber window
            With some sweet concert.              --Shak.
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            And boding screech owls make the concert full.
                                                  --Shak.
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   Concert pitch. See under Pitch.
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WordNet (r) 3.0 (2006):

concert pitch
    n 1: the pitch used to tune instruments for concert
         performances; usually assigns 440 Hz to the A above middle
         C [syn: concert pitch, philharmonic pitch,
         international pitch]