With her twinkling eyes, ready smile and palpable energy, you might guess that Mary Morrison is in her late 60s.

   But she turns 80 this fall.

   On a gorgeous spring midday, the interviewer suggests finding a park bench on Philosopher's Walk, outside the University of Toronto's Faculty of Music, where Morrison teaches.

   "Oh, I don't have time for park benches," she says firmly. So we head down to her studio in the Edward Johnson Building.

   The room holds a small grand piano at one end and a desk with two chairs at the other. It's a working space enlivened by postcards and pictures from her students, many of whom now enjoy international careers.

   "I get a lot of energy from the young people around me," she says.

   A signed black-and-white photo of Russian composer Igor Stravinsky, dated 1967, hangs by the piano hangs.

   "I was singing with the Festival Singers and we were recording (Stravinsky's) Symphony of Psalms. I gave him a bottle of Scotch and he gave me the picture," says Morrison, smiling.

   Morrison was Canada's pre-eminent concert and opera soprano in the 1950s and '60s and she remains a fierce champion of new music; her husband was composer Harry Freedman, who died last year.

   Multiply Morrison's energy by two, and you start appreciating how she and her husband became two of the most important figures in 20th-century Canadian music.

   Freedman and Morrison are the subjects of a tribute concert tomorrow night at the Glenn Gould Studio.

   The event will also launch a CD retrospective of Freedman's choral music (on the Centrediscs label), and a book biography of the musical couple titled Music Makers: The Lives of Harry Freedman and Mary Morrison, by Walter Pitman (Dundurn Press).

   Music Makers is not an exciting read. But Pitman's carefully researched look at two complementary artistic forces — creator Freedman and interpreter Morrison — is a quietly inspirational peek at the evolution of Toronto's musical life in the latter half of the 20th century, and of two people dedicated to their art and craft.

   The CD, The Tokaido, which includes a sampling of Freedman's most enduring choral pieces (for details, see Classical disc reviews at the back of the section), is excellent.

   The main interpreters on the disc, the Elmer Iseler Singers and the Amadeus Chamber Singers, led by Lydia Adams, are the main performers at tomorrow's concert.

   They will be joined by the Aeolian Winds and other instrumental guests.