Source : Webster's Revised Unabridged Dictionary (1913)

Solmization \Sol`mi*za"tion\, n. [F. solmisation, fr. solmiser
   to sol-fa; -- called from the musical notes sol, mi. See
   {Sol-fa}.] (Mus.)
   The act of sol-faing. [Written also {solmisation}.]

   Note: This art was practiced by the Greeks; but six of the
         seven syllables now in use are generally attributed to
         Guido d' Arezzo, an Italian monk of the eleventh
         century, who is said to have taken them from the first
         syllables of the first six lines of the following
         stanza of a monkish hymn to St. John the Baptist.

               Ut queant laxis Resonare fibris Mira gestorum
               Famuli tuorum Solve polluti Labii reatum, Sancte
               Joannes. Professor Skeat says the name of the
         seventh note, si, was also formed by him [Guido] from
         the initials of the two words of the last line; but
         this is disputed, Littr['e] attributing the first use
         of it to Anselm of Flanders long afterwards. The
         syllable do is often substituted for ut.

Source : WordNet®

solmization
     n 1: a system of naming the notes of a musical scale by syllables
          instead of letters [syn: {solmisation}]
     2: singing using solfa syllables to denote the notes of the
        scale of C major [syn: {solfege}, {solfeggio}]