The Collaborative International Dictionary of English v.0.48:

High-toned \High"-toned`\, a.
   1. High in tone or sound.
      [1913 Webster]

   2. Elevated; high-principled; honorable.
      [1913 Webster]

            In whose high-toned impartial mind
            Degrees of mortal rank and state
            Seem objects of indifferent weight.   --Sir W.
                                                  Scott.

   3. pretentious, pompous.
      [PJC]

WordNet (r) 3.0 (2006):

high-toned
    adj 1: pretentiously elegant; "a high-toned restaurant" [syn:
           high-class, high-toned]