"I must have seen 10,000 films," says Andress Taylor, a professor of English at the University of the District of Columbia whose research on the "blacksploitation" films of the 1970s is shaping up as a forthcoming book. "That was the primary form of entertainment when I was growing up."

The Black Film Institute's series "Black Music on Film," sponsored by UDC's Learning Resources Division and supported by grants from the National Endowment for the Arts, concludes next week with free screenings of "Leadbelly" (1976) on Tuesday and "St. Louis Blues" (1958) on Thursday. Both films will be shown at 6:30 p.m. in Room A03, Building 41, on the Van Ness Campus of UDC (take the Metro Red Line to UDC-Van Ness).

Taylor, who will be the guest speaker for Thursday's film, a biography of W.C. Handy starring Nat King Cole, sees the current successes of black actors and actresses such as Eddie Murphy ("Beverly Hills Cop") and Grace Jones ("A View to a Kill") as "a direct result of the work of Nat King Cole" in the 1950s. While it was Cole's "tremendous name recognition in another area" that won him roles in several films, Taylor says, his very image on the screen acted as "a kind of flying wedge to open up the general range of roles to black actors, thereby paving the way for black actors who were just actors and creating an audience accustomed to seeing black actors in lead roles."

Strictly speaking, Taylor points out, Cole was not a pioneer in the evolution of roles for black actors from the demeaning and stereotypical parts that had traditionally been their lot in the 1950s to the more rewarding roles blacks are beginning to enjoy. Ethel Waters, Lena Horne and others had already set the process in motion when Cole was cast as a French foreign legionnaire in "China Gate" (1957), his first film.

And while "St. Louis Blues" did not enjoy great financial success, the combined theme of the still-living legend "Handy" and Cole's achievement in "cross-fertilizing black soul and white popular music" introduced "a brief flowering of black actors playing different kinds of roles" in the '60s and early '70s. Taylor is confident that "in the future more and more Hollywood producers and directors will be more and more willing to use black actors in just any kind of role in basically white films."

As for "St. Louis Blues" itself, Taylor assesses the film's importance in terms of its historical significance and cultural impact, and, of course, its music. "Nat King Cole is much more of a singer than an actor, and Cab Calloway is always Cab Calloway," he says. The film also contains good jazz footage with Ella Fitzgerald and clarinetist Barney Bigard, as well as appearances by Mahalia Jackson and Pearl Bailey.

"Leadbelly," says Taylor, deals with the great singer-guitarist Huddie Ledbetter more as a folk hero than as an individual. "It was an attempt, it seems to me, to try to make a film that was equal to the legend," he says, "so it is not an accurate autobiographical film or documentary of Leadbelly's life." Director Gordon Parks "took the outward contours of the Leadbelly legend and simply fleshed it out. It's a beautiful film with just absolutely tremendous music." The lead role is taken by Roger E. Mosley (who has appeared on television in "Kojak" and "Baretta"), with "Hitide" Harris, Brownie McGhee and Sonny Terry providing the sound track.

The film has "a general sense of nostalgia about Leadbelly's early days," observes Taylor, "that second generation after slavery, with the emphasis on the dancing and the way the people made merry in the face of adversity made so attractive you wonder why anyone would want to get out. We go to a more sociopolitical perspective when Leadbelly goes to prison for killing a man in a fight, and it is in prison that he becomes an artist."