“We missed you, baby!” That was a typical shout-out from the packed Wang Theatre last Saturday, and little wonder: Canadian Celtic/new-age diva Loreena McKennitt hadn’t visited Boston since 1998, the year her fiancé, Ronald Rees, died in a boating accident. Back on the road behind last year’s An Ancient Muse (on her own now-Verve-distributed Quinlan Road label), her first release of new material since 1997’s The Book of Secrets , McKennitt, who’d just turned 50, looked as calm and ageless as the eternal verities she sings about. Whoops of recognition greeted the first notes of most of the 18 numbers, notably “The Bonny Swans,” and after the thunderous applause for that one (which rocked harder than it does on her recording, the drummer thumping on “false sister Anne”) had died away, there was a yell of “We like that!” McKennitt glowed: “I like this kind of dialogue with the audience. . . . Do you tour?”

Framed by the tent opening that appears on the Ancient Muse booklet, and moving among harp, accordion, and keyboards, in a long brown coat dress and brown underskirt, McKennitt drew equally on her four most recent full-lengths (1991’s The Visit and 1994’s The Mask and Mirror plus The Book of Secrets and An Ancient Muse ). Her nine-piece back-up, whom she called “the idling Porsches” because their talents outstrip her ability to make use of them, encompassed everything from hurdy-gurdy and bodhrán and Greek lyra to electric guitar and drum kit, a rock lion lying down with the world-music lamb, though often as not the last word went to violinist Hugh Marsh and cellist Caroline Lavelle. The set, similar to the one she played at the Alhambra last September (shown on WGBH last month and available as a DVD later this year), ranged from Ireland (“She Moved Through the Fair,” “Raglan Road”) and England (“The Bonny Swans,” “The Highwayman,” “The Lady of Shalott”) to Galicia (“Santiago”), Italy (“Dante’s Prayer”), Turkey (“The Gates of Istanbul”), Phrygia (“Beneath a Phrygian Sky”), Greece (the evening-ending “Penelope’s Song”), and the New World (“Huron ‘Beltane’ Fire Dance”), McKennitt tracing the putative wanderings of her Celtic ancestors and the heart’s unending quest with her trademark churchy harmonies and echo-chamber sonics. She fares best when she draws on the likes of Shakespeare and Tennyson and Yeats; her own lyrics tend to the “Cast your eyes on the ocean/Cast your soul to the sea/When the dark night seems endless/Please remember me” of “Dante’s Prayer,” and the invocation of a Celtic Everland under the banner of one world/one love/one God can seem glib. But she’s a marketing force, as the 10-deep lines for Loreena merchandise at intermission (what she playfully referred to as “station identification”) attest, and she knows how to put on a show. When you speak from the universe, audiences listen.