One of the good things about hard times is that human imagination is taxed. Different ways of doing things become the stuff of dreams, often out of necessity.

Perhaps the best new idea in Washington during recent months became a reality last week on the F Street Mall in downtown D.C.

There, a corporate-style venture designed to aid the performing arts was opened by the Cultural Alliance of Greater Washington--itself a rather young player in a small but expanding partnership between the huge arts community here and Washington business.

Ticketplace is the name of the Cultural Alliance's venture, a ticket booth between 12th and 13th streets NW. Its contribution to theater, music, art and the dance in metropolitan Washington could exceed $1 million a year, at a time when both established and avant-garde arts organizations are strapped for money.

For a sober look at how one major group, the National Symphony Orchestra, reorganized its fund-raising activities, your attention is invited to colleague Robert S. Graettinger's account on page 44 of today's Washington Business.

Whatever the financial outlook for the NSO or any of dozens of smaller arts organizations in future years, their plight is bound to be reduced somewhat by the contribution of Ticketplace.

According to Peter A. Jablow, executive director of the Cultural Alliance, more than 1.1 million tickets to cultural and arts performances in the area go unsold every year. To help fill many of these empty seats, here's how Ticketplace will work:

Every day except Sundays, the ticket booth will be open from 11 a.m. to 7 p.m. On each day, half-price tickets for that day's performance are available on a cash-only basis. It's first-come, first-served until tickets for a particular show or concert are gone. Half-price tickets for Sundays, when the booth will be closed, also are on sale Saturdays.

A computerized ticket system provides the next-best seat available for any area arts performance, Jablow said. There is a service charge of 50 cents for each $10 face value of each half-price ticket. Ticketplace also sells full-price tickets for advance dates (for which credit cards may be used), with a $1 service charge for each ticket. But the major advance for the arts comes from filling additional seats even at cut-rate prices while the service fees help cover costs of operating the booth.

Jablow emphasized that a ripple effect from Ticketplace's operation should sell even more tickets. For example, when Ticketplace opened for business at a gala "Jump for Joy, Washington Goes Half-Price" celebration last Tuesday, one of the first persons in line wanted -- naturally -- the hottest ticket in town, to "Evita" at the National Theatre. That show was sold out for Tuesday, but the customer purchased a half-price ticket for "Kingdoms" in the Kennedy Center's Eisenhower Theater.

And, as a consolation, the first 25 ticket purchasers on Tuesday did get "Evita" posters autographed by stars of the National company.

At the start, more than 65 organizations are taking part in Ticketplace, including Ford's Theatre, Arena Stage, Washington Performing Arts Society, Washington Ballet, Washington Opera, Alexandria Choral Society, Choral Arts Society of Washington, Folger Theatre, Prince George's Little Theatre and the University of Maryland's varied arts programs.

Ticketplace is a new idea for Washington, but it is not unique. New York has a similar operation called TKTS and Boston has Bostix. In New York, a single ticket operation with several windows in lower Manhattan has added $2.5 million of revenues a year to performing arts groups by selling seats at half-price on the day of performance, Jablow said.

His organization, the Cultural Alliance, was founded in 1978 and was patterned after similar organizations in other cities. It is a nonprofit service organization designed to help artists and to forge links with other community sectors -- business, labor, government.

If the Cultural Alliance is not a unique organization, its challenge in metropolitan Washington is. Although the employment mix has changed considerably here in recent years, with growth of the private sector, government still dominates in many ways and there is not the large industrial or corporate population of a Cleveland, New York, Chicago, Boston or Philadelphia to help fund home-town arts.

Working with other groups, the Cultural Alliance is completing a census of the arts in the Washington area to provide some tools in seeking aid for an increasingly important economic as well as cultural element of this community's life. A full report is expected by early December, and Jablow said last week he expects the figures to show Washington as second only to New York in terms of economic activity related to the arts.

Among other innovative approaches to long-term financial support of the arts, Jablow's organization is a participant in one of five major development proposals for the so-called Portal Site at the end of the 14th Street Bridge in Southwest Washington. The Redevelopment Land Agency is expected to pick one of the development plans within the next month and lobbying for the various groups, each of which includes prominent community participants, is reported at a fever pitch.

Specifically, the Cultural Alliance is part of a proposal by Portal Associates Limited Partnership, headed by developer Conrad Cafritz as managing partner and Tyroc Construction Corp. owner Roger Blunt as codeveloper and general contractor. The Cafritz plan, designed by the architectural firm of Skidmore, Owings & Merrill, includes a 250-seat theater and an art gallery, both of which would be subsidized by the overall project.

Arts groups would get 1.5 percent of office and parking revenues in the entire project, as well as one percent of hotel revenues -- which Jablow projected to more than $1 million a year for the arts in 1990.

Whatever the outcome of the Portal Site bidding war, this is a "landmark idea" for the arts in Jablow's view because it sets a precedent he hopes other developers and community groups will follow. A canvass of other cities indicates that no similar arts-project development plan has been worked out in advance with a builder, he said.

In a variation of this theme, Jablow is planning to make a presentation to the Pennsylvania Avenue Development Corp. -- perhaps later this week -- in which he suggests that formal agency development offers to builders include a requirement that a certain percentage of the project's income be applied to support for the arts.

Washington is unchallenged as the world's political center. It is becoming an important regional business headquarters. Growth as a cultural center has been so rapid that some of the necessary financial underpinnings have not been put in place. With ideas like Ticketplace and the sharing of development revenues, the Cultural Alliance is making a major contribution to belated construction of a permanent foundation for the arts.