Which preposition to use with harmonizers

of Occurrences 1%

Thus, the hair-bird (Fringilla Socialis) has a sharp and trilling note, without any modulation, and not at all melodious, when heard alone; but in the morning it is the chief harmonizer of the whole chorus, and serves, more than any other voice, to give unity and symphony to the multitude of miscellaneous parts.

Which preposition to use with  harmonizers