The 50-voice a cappella choir Magnum Chorum celebrated the season Saturday night with a program titled "Celestial Spring." The strong performance, heard at Nativity of Our Lord Catholic Church in St. Paul, was enough to inspire spring fever despite the unseasonable temperatures.

Magnum Chorum produced a mature, burnished sound, fuller than some ensembles twice its size. Under music director Christopher Aspaas, they demonstrated a clarity of tone that stands them in the first rank of Twin Cities choirs.

The intriguing program was a veritable history of choral music in Minnesota. The final work gave the concert its name. The four motets by F. Melius Christiansen, founder in 1911 of the St. Olaf Choir, were a pioneer work in the art of a cappella singing.

His son, Paul J. Christiansen, spent his career leading the Concordia Choir in Moorhead. He was represented by "The King of Love," a work of utter simplicity that the choir sang with the utmost purity.

René Clausen, current conductor of the Concordia Choir, continued that tradition with the technically demanding "Canticle of Praise." Magnum Chorum made the complex tone clusters sound easy. They then brought the tradition up to date with two compositions by Stanford E. Scriven, a St. Olaf junior, works that promise an illustrious career.

It's hard to find a more evocative setting of texts than Stephen Paulus' "Prairie Songs." They managed to be both lush and austere, and were profoundly moving. The only complaint that could be lodged is that Magnum Chorum only performed three of the six songs set to 19th- and 20th-century American poems.

Beyond Minnesota, the program spanned the full history of American choral music, from William Billings, the 18th-century founder of the American choral tradition, to Eric Whitacre, the current celebrity among choral composers. Billings' rousing "Easter Anthem" had the feel of a Handel chorus, while Whitacre's subdued "A Boy and a Girl" was a disappointment in this company.

There was also an international flavor, from English Romantic Charles V. Stanford and his robust Three Motets, to Swede Hildor Lundvik and his three gentle and spare Nocturnes, to Canadian (though born in Faribault, Minn.) Stephen Chatman and his boisterous "Elizabethan Spring," three modern madrigals.

Aspaas was a strong leader, if a bit overeager, with long and enthusiastic introductions. The music spoke for itself.

William Randall Beard writes regularly about music.