2012 has been a prominent year for anniversaries in music. Philip Glass was born 75 years ago, John Cage 100 years ago, Claude Debussy 150, and Arnold Schoenberg’s Pierrot Lunaire, crucial in the revolutionary composer’s development, celebrates the centennial of its premiere, along with Gustav Mahler’s Ninth Symphony. And then there is Oberlin’s Musical Union, stretching back farther than any of those as the second-oldest continuing choral group in America; 2012 marks its 175th year of existence.

In honor of that anniversary, the Musical Union joined forces with the Oberlin Orchestra and the College Choir on Sunday to present Mozart’s Great Mass in C minor, K. 427.

Dean of the Conservatory David Stull prefaced the concert with brief remarks congratulating the Musical Union on continuing such a long, auspicious tradition. With obvious pride, he related the origins of the ensemble: In 1837, only four years after the College was founded, a group of students petitioned the administration to form a musical ensemble. Taken on by Professor of Sacred Music and Geology and Natural History George Nelson Allen, the Musical Union was the first step toward establishing a Conservatory of Music. Allen used the Musical Union concerts to fundraise for musical contributions to the College and was instrumental in launching the Conservatory in 1865.

A Mass with the moniker “Great” is fitting for an ensemble that began before the Civil War and has existed in three distinct centuries. And Mozart’s Mass lives up to the name.

It opens with an austere Kyrie that showcases the composer’s Mozart’s polyphonic skill. After the implorations of the full chorus and orchestra, a soprano soloist enters with an expressive solo. On Sunday, Ellie Dehn, OC ’02, sang the part with impressive technique and engagement.

The meat of the Mass, which was left unfinished for unknown reasons, resides in the Gloria, which contains eight alternating choral and solo sections. Dehn and fellow soprano Marcy Stonikas, also OC ’02, were especially memorable in their duet, the “Domine Deus” section. The two vocalists alternated high notes at the end of the duet, coming in one after the other to lend passion to an already impassioned movement. Director of the Division of Vocal Students Salvatore Champagne, OC ’85, joined the soprano soloists as a tenor in a trio on “Quoniam tu solus sanctus,” reminiscent of Baroque music in its counterpoint and driving harmonies. The Gloria ended with a choral explosion on “Jesu Christe,” followed by a glorious fugue that, under the direction of Jason Harris, was sure-handed and stirring.

The most remarkable moment of the Mass came in the Credo, with the soprano aria “Et incarnatus est.” Featuring flute, oboe and bassoon along with Ms. Dehn, the movement unraveled phrases that glittered in their simplicity and earnestness. The cadenza at the end was impossibly lyrical as the woodwinds entered a dialogue with the soprano, intricately spiraling among each other in sweet arabesques.

After another choral outburst in the Sanctus, an energetic fugue began that tested the endurance and virtuosity of the chorus. The Oberlin musicians pulled it off with joy.

The mass ended with a Benedictus, in which the bass soloist finally was given a chance to sing in a vocal quartet. Associate Professor of Singing Timothy LeFebvre brought a powerful voice to complement the other three soloists in another highly contrapuntal movement that ended with full chorus in the magnificent manner expected of a mass.

The Musical Union’s rich and expansive history was felt in the zealous applause given to the many talented musicians who joined together to commemorate an important source of Oberlin’s musical heritage.