Nova Scotia's Stirring Voice. MUSIC: INTERVIEW

SINGER Rita MacNeil doesn't wow her audience with theatrics. Instead, this meek woman from Nova Scotia woos listeners with the sheer power of song. Ms. MacNeil's warm voice and impassioned lyrics have stirred Canadian sentiment from the Maritimes to Vancouver for the last few years. Now she's making her way south, introducing her down-to-earth themes to attentive American audiences (and to a good many transplanted Canadians as well).

MacNeil's United States debut here at the Berklee School of Music recently illustrated how this untutored singer and composer has earned success in her home country: through heart-to-heart songs delivered in ``take me as I am'' fashion. She offers thoughtful messages of love and heartache, trials and triumphs, based on her own personal experiences.

``I'm a Canadian for sure,'' said MacNeil in her Boston hotel room before the concert. ``But the music is universal. It's emotions that I write about.''

Simple words set to singable melodies are MacNeil's trademark. ``People are looking for honesty, something real,'' she remarks with a lilting Canadian cadence. She has attracted enough fans with this singing style to earn a Canadian ``Grammy'' - the Juno Award in 1987 for Most Promising Female Vocalist. Her three albums, ``Flying on Your Own,'' ``Reason to Believe,'' and a recent Christmas album (all three on A&M, Toronto), have all reached platinum status (over 100,000 sold) in Canada.

``I never dreamed this could happen to me,'' says MacNeil, a single mother of two college-age children, who hails from Big Pond, Nova Scotia (pop., 75).

``It's taken a long time. When you don't look a certain way or fit into a category, it's always hard to break through,'' she says, describing her struggle to win acceptance from the Canadian popular-music industry. Years ago, she sometimes worked as a cleaning lady to make ends meet while raising her children and pursuing her singing career.

At the Berklee concert, one was not impressed so much by her large figure, draped in shimmering silver, as by her cherubic face smiling out shyly from beneath a broad-rimmed hat. In a move her fans have come to expect, she appeared in stocking feet for the show's second half.

Rita MacNeil seems to ride on a tide of empathy she creates with her listeners, bolstering her lyrics with imagery and emotions that connect to real life. In concert, her heart-rending performance of ``Reason to Believe,'' a song she wrote in memory of her mother, was balanced by her witty account of a predawn hotel fire drill that left her in embarrassing straits.

``It feels like you know her,'' remarked Joan McMackin, an audience member who heard about MacNeil through relatives living in Nova Scotia. ``Her songs give you a bit more hope about your life,'' she added.

When starting to write a song, explains MacNeil, she thinks of some strong feeling or emotion, such as love or fondness for a special person or place. Having no instrumental training, she composes in her head and then sings the composition to her five-piece band.

``When the song is finished, it could be country, blues, rock, or folk. I don't have any preconceived notion of how a song will turn out,'' she says.

Set to traditional folk and country harmonies, tunes like ``She's Called Nova Scotia,'' a gentle waltz MacNeil wrote on tour while homesick for her Cape Breton, stick in the memory. ``Flying on Your Own,'' a song about gaining courage and self-confidence, has been a landmark number off the album of the same name

``Working Man'' celebrates the past labors of retired miners in Nova Scotia, who once gave MacNeil a tour of their closed mines. After hearing about the hardships they endured, she wrote the anthem, which builds to a dignified climax. Says MacNeil: ``You don't have to be from Cape Breton to relate to that song.''