The renovation would take 22 months and would include more seats -- 2,400 from 2,067.

The Auditorium, listed on the National Register of Historic Places and the Denver Landmarks List, opened in 1908 and hosted the Denver National Convention that year. But it hasn't been renovated since 1955. It could be closed if its aging mechanical and structural systems are not updated.

The Auditorium along 14th Street is down the street from the $268-million convention center expansion project. The renovation plans call for creation of a proscenium theatre designed around unamplified natural acoustics.

In addition to the $75-million renovation, a task force recommends another $20 million in options.

Using $50 million in funds collected or repaid from seat tax revenues, and $25 million in general obligation bonds would fund the $75 million. That would need to be approved by voters.

In other words, two-thirds of the cost of the renovation can be directly paid by users of the theatres through seat tax revenue.

A $25-million bond issue would add less than $1 a month to the average Denver homeowner's property tax bill. The additional $20 million likely would be raised from private fund-raising.

In addition to Webb, the project is endorsed by the Denver Metro Chamber of Commerce, the Denver Public Schools, the Denver Metro Convention and Visitors Bureau, the Colorado AFL-CIO, the Denver Area Labor Federation, the Colorado Business Committee for the Arts, the Mayor's Commission on Art, Culture and Film and Historic Denver Inc.