There's not a great quantity of watchable television on tap this evening, but what there is boasts a very high level of quality. Leading the list: a camp musical and a sober and sobering documentary.
* "I'll Fly Away" (8-9 p.m., WETA-Channel 26) -- Something as simple as a little boy's lost hat leads to misunderstandings and prejudicial charges in this first one-hour episode of "I'll Fly Away." Sam Waterston, Regina Taylor star. PBS repeat.
* "The Rocky Horror Picture Show" (8-10 p.m., WBFF-Channel 45) -- Have you been awaiting the world TV premiere of this 1975 cult film with "antici-PA-tion"? Then you probably know all about this movie, which spoofs sci-films and uptight attitudes in an intentionally outrageous and camp musical. Tim Curry stars as "a sweet transvestite from transsexual Transylvania," which tells you just about all you need to know -- except that the young couple he tries to corrupt is played by Barry Bostwick and Susan Sarandon. Fox.
* "The Great Depression" (9-11 p.m., WMPT-Channel 22) -- VCR Alert: Until now, only two PBS documentary miniseries have produced works of art by bringing to life a key period of American history: Henry Hampton's "Eyes on the Prize" and Ken Burns' "The Civil War." Beginning tonight, with Hampton's "The Great Depression," there's a third. "The Great Depression" is a brilliant team effort, and these first two hours explain the start of the Depression in novelistic, humanistic, thoroughly dramatic terms. "The Great Depression" continues through Thursday on PBS, and viewers ought to tape and savor the entire series. PBS.
* "Northern Exposure" (10-11 p.m., WBAL-Channel 11) -- Maggie (Janine Turner) as homecoming queen? Don't count it out -- if she accepts the offer of a date from a high-school admirer. CBS.
* "The Jon Stewart Show" (10-10:30 p.m., MTV) -- I haven't seen this new MTV series, but I HAVE seen the ads running on MTV: middle-aged, overweight guys in old-fashioned bathing suits, diving sequentially into a pool, Busby Berkeley-style, as their shirts spell out J-O-N S-T-E-W-A-R-T. Or the same guys, sitting in one end of the pool, discussing a variety of topics with mock new-age sensitivity. If the show's as offbeat as its promos, "The Jon Stewart Show" is one to watch.