§ 424. Institute of arts and sciences. Real property which may
hereafter be acquired within a city having a population of one million
or more by a corporation, organized exclusively as an institute of arts
and sciences for the general purposes of the encouragement of the study
of and the advancement of knowledge in the arts and sciences within such
city on which a building has been constructed as an academy of music
which is maintained and operated by such corporation as such and to
otherwise further the purposes for which such corporation was organized,
shall be exempt from taxation including the buildings thereon as
provided for corporations in section four hundred twenty-a of this
article although a portion thereof is leased or otherwise used for the
public performances of opera or concerts, lectures, graduation exercises
or for such other non-commercial uses for the purposes of income, if
such income is necessary for and is actually applied to the maintenance
and support of such academy of music.