This did not seem to Bok a sound business plan; it made of the orchestra a necessarily exclusive organization, maintained by a few; and it gave out this impression to the general public, which felt that it did not "belong," whereas the true relation of public and orchestra was that of mutual dependence.

Other orchestras, he found, as, for example, the Boston Symphony and the New York Philharmonic had their deficits met by one individual patron in each case.

This, to Bok's mind, was an even worse system, since it entirely excluded the public, making the orchestra dependent on the continued interest and life of a single man.
In 1916 Bok sought Mr.Alexander Van Rensselaer, the president of the Philadelphia Orchestra Association, and proposed that he, himself, should guarantee the deficit of the orchestra for five years, provided that during that period an endowment fund should be raised, contributed by a large number of subscribers, and sufficient in amount to meet, from its interest, the annual deficit.

It was agreed that the donor should remain in strict anonymity, an understanding which has been adhered to until the present writing.
The offer from the "anonymous donor," presented by the president, was accepted by the Orchestra Association.

A subscription to an endowment fund was shortly afterward begun; and the amount had been brought to eight hundred thousand dollars when the Great War interrupted any further additions.