DETROIT (AP) — The Detroit Symphony Orchestra says four foundations are giving a combined $18.5 million to the organization to boost programming and its permanent endowment.

The ensemble said Monday the lion's share — $15 million — comes from the William Davidson Foundation. The contribution from the longtime benefactor continues its sponsorship of the orchestra's Neighborhood Concert Series.

The Davidson Foundation gift includes a $5 million challenge grant to encourage additional support for the endowment. The orchestra says that challenge is halfway met with contributions from The Andrew W. Mellon Foundation, Fred A. and Barbara M. Erb Family Foundation and Dresner Foundation.