“Who can turn the world on with her smile?” This opening line describes Mary Tyler Moore in her namesake sitcom’s upbeat opening theme song “Love Is All Around” — a tune that fits the show’s optimistic themes.

Moore plays Mary Richards, a single woman who moves to a Victorian apartment in Minneapolis and quickly lands a job as associate producer at local news station WJM-TV. Mary and her Bronx-born neighbor, Rhoda (Valerie Harper), soon form a pair of unconventional best friends.

With a plethora of amazing clothes in her closet, Moore’s acting is incredibly natural as she epitomizes an ultra-friendly version of the “everywoman.”

At the station, a handful of characters bring regular laughs: Lou Grant (Ed Asner) is Mary’s short-tempered boss and semi-father figure. Sue Ann Nivens (Betty White) hosts “The Happy Homemaker,” although she irks her coworkers behind the scenes. Witty copywriter Murray (Gavin MacLeod) lives to make sarcastic remarks about Ted Baxter (Ted Knight), the station’s anchorman — whose arrogance is constantly inflated to hilarious and absurd proportions.

Side characters also get a chance to shine, including Phyllis, Mary and Rhoda’s older, extravagant neighbor, and Georgette, Ted’s sweet yet simple-minded wife.

Valerie Harper summed it up perfectly in a 2013 interview with the cast: “Mary is who you wish you were, Rhoda is who you probably are and Phyllis is who you’re afraid you’ll become.”

Most episodes will see Mary and Rhoda swapping tales about recent dates they’ve been on or the daily antics of the newsroom, often involving ridiculous situations resulting from Ted’s ego.

Mary Richards is a far cry from Moore’s previous housewife role on the black-and-white “Dick Van Dyke Show” (1961-1966). Despite there being no connection between the programs, it’s hard to believe she’s the same actress when the two are viewed back-to-back.

In “The Mary Tyler Moore Show,” Moore appears to have found herself. Funny, relatable and at times poignant, this 1970s series is a hit for all decades.