ANGELA SINGS `MRS. CLAUS' : SHE'S MAKING THINGS RIGHT BACK IN HER OLD SUNDAY SLOT.

Byline: Keith Marder Daily News Television Writer

Angela Lansbury is back on CBS' Sunday night lineup. Still at 8 p.m.

But tonight, Jessica Fletcher won't be there with her.

Rather than the sleuth she played in that time slot for more than a decade, Lansbury will play ``Mrs. Santa Claus'' in a musical that shows what would happen if the wife of the famous toy distributor was dispatched to cure all that's wrong in the world.

It's a sweet story set in 1910 when Mrs. Santa Claus ends up in the Alphabet City - Avenue A to be exact - section of New York, then straightens out everyone from wayward children to an evil toy factory owner. She makes the melting pot region a better place to be.

Unlike ``Murder, She Wrote,'' nobody dies in this one.

The show is a virtual Tony-fest. Jerry Herman, the man behind the music, has won for ``Hello, Dolly!'' and ``La Cage aux Folles,'' plus served as music man for ``Mame.'' The cast contains two other Tony winners: Charles Durning (Santa Claus) and Michael Jeter (Arvo, Santa's head elf). Terrence Mann, a two-time Tony nominee, plays the bad guy, Augustus P. Tavish, who runs the sweat shop of a toy factory.

Lansbury said that she felt it imperative that the movie show in the same time period that made ``Murder, She Wrote'' one of the television's most-watched shows ever.

``They were going to put it on at 9 o'clock,'' Lansbury said, ``but I said, `Please give me my old time slot, children can't stay up until 11 o'clock and this is for the whole family.' ''

Time slot has been a sore point in Lansbury's TV career; the controversy surrounding the scheduling of ``Murder, She Wrote'' was well publicized. Having enjoyed one of the most successful runs in television history - from 1981 until this past season - CBS entertainment president Les Moonves decided as part of the ill-fated younging-down of CBS that he would move ``Murder'' and put it up against NBC's juggernaut ``Friends.''

In theory, the older audience would leave NBC at that time and CBS would chip away at televison's most dominant night.

It didn't work. In the first case even Jessica Fletcher couldn't solve, ``Murder'' was killed off.

``I loved it, it was great until it was coming to the end when, you know, the balloon burst ahead of its time,'' Lansbury said. ``But all that's over now.''

``Mrs. Santa Claus'' is part of the golden parachute deal CBS made for Lansbury that included several movies. Next year she will unveil two two-hour ``Murder, She Wrote'' television movies. She is also working on a sequel to ``Mrs. 'Arris Goes to Paris''; this time the cleaning lady from London will travel to New York.

Lansbury said she misses Jessica - the two women became more and more alike through the years - but she appreciates ``Mrs. Santa Claus'' for giving her a chance to get back to some of her acting roots.

`` `Mrs. Santa Claus' was a God-given opportunity for me; in a way I have to say that I grabbed it,'' said Lansbury, a four-time Tony Award winner.

``After 12 years of doing television and playing the lovely Jessica Fletcher, it was a dream to get back to singing.''

``Mrs. Santa Claus'' is the first made-for-television musical since Rodgers and Hammerstein's ``Cinderella'' about 40 years ago, Lansbury said, and she wonders if it could spawn a new generation of television musicals.

``I hope it will,'' said Lansbury, whose 11-year-old granddaughter, Katherine Shaw, is learning show tunes in her singing and dance classes.

``There will be some awful mistakes made, but I hope there will be some winners, too. Perhaps some of these new young writers will be able to find new inventive ways to write musicals. Children and adults love music and love musical theater and see so little of it.

``I'm amazed to hear that they are doing `Sweeney Todd' in some high schools, and as someone who has been in it, I can say that it is a difficult proposition. I'm encouraged that they have the excitement and the ambition. We are going back to the old, singable songs. We miss standards. We miss singable music, particularly the baby boomers - they miss it.''

There have already been stage musicals adapted for television. A recent example is ``Bye Bye Birdie.''

``I was sorry to say that although there were some good performances (read: Jason Alexander), it did not adapt well to television,'' Lansbury said. ``Gypsy'' - which she has performed in - worked better on television, she said, because ``Bette Midler shone through.''

One of the things that attracted Lansbury to ``Mrs. Santa Claus'' was Herman's involvement. A 47-piece orchestra was employed to record all the music for the show before filming even started.

Although she digs the singing gigs, Lansbury said that she probably would not return to Broadway unless ``somebody had a brilliant idea to do something that was applicable to a lady of my years and experience that would run for a limited time.

``Usually they need a longer run to get their money back.''

A return to a television series is not in the 71-year-old actress's future, either. ``Murder, She Wrote'' was somewhat of a grind - Lansbury was in almost every scene, making for long days, weeks and seasons.

``Suddenly, I have the time I never had before,'' Lansbury said. ``I love the regularity of (the series); it suited me very well. I don't know how one can

plan one's life nine months ahead. We knew where we had to be at any given time. The structure was very comfortable, but it was also very suffocating. Every eight days we made a one-hour movie, and on the ninth day we started again. It wasn't like a sitcom where you work for three weeks and had 10 days off.''

Theatrical movies are more likely. But while Lansbury sees the production of family fare for television as a paramount concern, she is willing to go further with her big-screen persona. For instance, she said she would like to do something as daring and ``incredibly innovative'' as her part of Raymond's controlling, incestuous mother in ``The Manchurian Candidate.''

She says her health is no obstacle. And hip replacement and all, she looks wonderful singing and dancing in ``Mrs. Santa Claus.''

``I feel darn good,'' she said. ``I don't feel old for one minute. I just don't want to go at it as hard as I did.''

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2 Photos

Photo: (1--Cover--Color) Christmas, she wrote

Angela Lansbury returns to her TV home as `Mrs. Santa Claus'

(2) Four-time Tony award winner Angela Lansbury stars in ``Mrs. Santa Claus,'' the first original musical for television in four decades.