ON AND OFF THE AIR:
* Have a little R-E-S-P-E-C-T for Sam (Scott Bakula). In tonight's edition of NBC's "Quantum Leap" (at 10, Channel 2), he finds himself occupying the person of a talented black teen, a member of a singing trio in the early 1960s.
The problem involves another singer in the group (Tammy Townsend), whose minister father wants the combo to sign with a crooked manager. (T'Keyeh "Crystal" Keymah, from the Fox series "In Living Color," is the third member of the trio.)
The network also offers a hint at the origin of the idea, by noting series co-executive producer Deborah Pratt, who wrote the script, once was a member of the "Golddiggers" song-and-dance troupe of TV's "Dean Martin Show."
* On the cable connection, the TBS basic service tonight launches a five-film marathon over the next three nights of "Perry Mason" murder mysteries.
They are all from the revival series on NBC, and the first (at 8:05 tonight) is "Perry Mason: The Case of the Murdered Madam," with Ann Jillian as the title character.
* On the radio beam, WBAL-AM 1090 tomorrow afternoon is planning to air a three-hour "Neighborhood Crime Summit."
"The Ron Smith Show," from 1 to 4 p.m., will include guests Governor Schaefer, state public safety secretary Bishop L. Robinson and State Police chief Elmer H. Tippett responding to calls from listeners about crime issues in the state.
* Here's a turn-the-tables item involving this week's episode (Monday) of the CBS series "Murphy Brown:"
The Candice Bergen show, of course, has often had fun by mentioning or even offering cameo appearances by real broadcast news figures. But how often has the comedy show been cited in a news interview?
National Public Radio commentator Nina Totenberg did so on Monday's edition of "CBS This Morning." For just as the fictional Murphy refused in Monday's show to tell a U.S. Senate committee the source of a story, Totenberg is being pressured by the Senate to reveal who leaked her the news last fall of Anita Hill's sexual harassment charges against Supreme Court nominee Clarence Thomas.
And under questioning from Paula Zahn, Totenberg cited "Murphy Brown" as having correctly stated the issue of press freedom to use confidential sources.