The best documentaries tell you something you do not already know. And if you're really lucky, they will contain a story as good, or better than, a Hollywood film.

The "American Masters" (9 p.m., PBS, TV-PG) presentation of "Sister Ro setta Tharpe: The Godmother of Rock & Roll" clicks on both

cylinders. It's a can't-miss for fans of pop

culture and

music history.

Gone 40 years, Tharpe

offered a remarkable link

between the worlds of gospel, big band, rhythm and blues,

boogie-woogie and what became known as rock 'n' roll. And she did so while playing raw, bluesy, muscular riffs on an electric guitar long before such performances were seen as

ladylike or fit for a singer of

spirituals.

Her life was as colorful, tragic and cinematic as her performances. Born to a poor farmer/musician and a self-taught evangelist, Tharpe was just a child when she began to accompany, and then quickly outperform, her mother on the evangelizing circuit. Her mother took Rosetta out of the South, moving to Chicago and having a controlling influence on her for most of her life. She later married her daughter off to a cruel and exploitive

preacher.

Tharpe's decision to leave that marriage coincided with her entry into the secular, often profane popular music of New York's Cotton Club and other big band venues. Her departure from pure gospel, which came decades before Ray Charles and Sam Cooke made similar creative decisions, was seen as a betrayal. She continued to bridge the two worlds and sing spirituals as Sister Rosetta.

Her personal life included several semipublic relationships with other women, including longtime collaborator Marie Knight. Having been victimized by an arranged religious marriage in her youth, Tharpe orchestrated a brazen public wedding ceremony in 1951, marrying a music manager she barely knew in front of 25,000 fans at Griffith Stadium in Washington, D.C. The stunt worked, but the marriage foundered.

"Sister" includes great, but sadly, rare archival footage of her performances, as well as interviews with peers, the children of peers and members of the gospel groups the Dixie Hummingbirds and the Jordan-

aires, Elvis Presley's vocal accompanists, who broke the color barrier by performing with Tharpe during the years of strict racial segregation.

It would have been nice to hear from the legends (Chuck Berry, Jerry Lee Lewis and Little Richard) Tharpe influenced. And some of the

narration leans toward the perfunctory. But this "American Masters" goes to the top of the charts in my book. At a time when many rock histories offer cliche-ridden meditations on the all-too-familiar, "Sister" provides curious viewers that rarest of treats: unexplored

territory.

OTHER HIGHLIGHTS

---A retirement sparks a crisis on "Kitchen Nightmares" (8 p.m., Fox, TV-14).

---Wildcats face harsh conditions in the northern Rockies on "Ameri can Cougar: Revealed" (8 p.m., National Geographic). And you thought this was a profile of Demi Moore.

---The shooting of an unarmed man outrages the public on the season finale of "CSI: NY" (9 p.m., CBS, TV-14).

---Crassus turns to old-school torture on "Spartacus" (9 p.m., Starz, TV-MA).

---Danny and Erin re-examine an assault case against a tycoon on "Blue Bloods" (10 p.m., CBS, TV-14).

---A young Druid needs the

wizard's assistance on "Merlin" (10 p.m., Syfy, TV-14).

---Stan's fish supply runs low on the season premiere of "Yukon Men" (10 p.m., Discovery, TV-PG).

---Carrie threatens to blow Lucas' secret on "Banshee" (10 p.m., Cinemax, TV-MA).

---Rats flee a gentrifying ship on "Portlandia" (10 p.m., IFC, TV-14).

---Fred Armisen ("Portlandia"), Linda Cardellini ("Freaks and Geeks"), John DiMaggio ("Adven ture Time") and Megan Mullally ("Party Down") voice the cartoon comedy "Out There" (10:30 p.m., IFC, TV-14).

CULT CHOICE

The savage reviews for the 2011 Adam Sandler-in-a-dress comedy "Jack and Jill" (8 p.m., Encore) were much funnier than the film.

SERIES NOTES

---A hotel chain sets out to hire on "The Job" (8 p.m., CBS, TV-PG).

---Mike celebrates on "Last Man Standing" (8 p.m., ABC, TV-PG).

---Amanda frames Sean on "Nikita" (8 p.m., CW, TV-14).

---Not-so-friendly competition on "Malibu Country" (8:30 p.m., ABC, TV-PG).

---Martin gives his all on "Touch" (9 p.m., Fox, TV-14).

---Sustainable glasses raise eyebrows on "Shark Tank" (9 p.m., ABC, TV-PG).

---A popular show may be more fact than fiction on "Cult" (9 p.m., CW, r, TV-14).

LATE NIGHT

---Julianne Hough, Jeff Wild, Heather McDonald and Nico Santos appear on "Chelsea Lately" (11 p.m., E!, r).

---Dan Mintz and Bill Carter and the Blame appear on "Late Show With David Letterman" (11:35 p.m., CBS).

---Jay Leno welcomes Meredith Vieira, Richard Roeper and thenewno2 on "The Tonight Show" (11:35 p.m., NBC).

---"Jimmy Kimmel Live" (11:35 p.m., ABC) glances back at the past week.

---Michelle Obama and Scarlett Johansson visit "Late Night With Jimmy Fallon" (12:35 a.m., NBC).

---Craig Ferguson hosts William Shatner and Alona Tal on "The Late Late Show" (12:35 a.m., CBS).

Kevin McDonough can be reached at kevin.tvguy@gmail.com.