Mendelssohn Clubs popped up across the country starting in the late 1800s, but Missoula is now home to the one of the last, and by default, longest-running ones in the United States.

On Sunday, the Missoula Mendelssohn Club will mark its 70th spring concert with the help of the Montana A Cappella Society.

The club is holding strong with 25 to 30 singers, all non-auditioned members of the community.

They range in age from 19-year-olds to octogenarians. Their occupations vary from former police officers to doctors and investors to students.

"It encourages that kind of variety of community," said conductor Dean Peterson.

"They're goodhearted guys – they'll try just about anything," he said.

One of those guys is Harold Hanger, a Missoula native who served in World War II and the Korean War.

Hanger, who sings second tenor, signed up in 1954 after he got out of the Navy.

"My dad was singing at the time, so I joined him in the Mendelssohn Club," he said.

He's been a member ever since, although there were gaps here and there when he left the club as life demanded.

He's most proud of going on one of the club's trips to Europe, and the first year of the International Choral Festival, the triennial Missoula event that was founded by members of the club.

It brings hundreds upon hundreds of choir members from around the world to the Garden City.

"It's been real good for the city of Missoula," he said.

He's stayed a member of the club because of the camaraderie, and the variety of music that they get to sing. Each conductor – he's sung under five now – has their own preferences, so he's covered a lot of musical ground.

For Sunday's concert, Peterson combed through the archive of programs from the 1950s to the present to find particular themes or pieces that the club returned to again and again.

Some of those will appear on Sunday's program, such as "There Is Nothing Like a Dame" from the musical "South Pacific," "The Whiffenpoof Song" from the Yale Glee Club and Verdi's "La Vergine Degli Angeli," which will feature soprano Elin Peterson.

Also at the concert, they'll perform an arrangement of "America the Beautiful," accompanied by the Brass Quartet, in honor of Don Carey. The longtime conductor is credited with bringing challenging arrangements and levels of performance to the group.

Peterson, who also leads the Missoula Symphony Chorale, was hired in 2011 to fill the post.

He said the club has a less intense performance schedule and a wide range of material to choose from – sailor shanties, Western songs and more. The sound of the choir itself is "unique and very inspirational," he said.

They meet every Monday for rehearsal during their October to March rehearsal season.

Their performances include two major concerts per year – a performance in Hamilton in December with the Montana A Cappella Society and the spring concert here in Missoula.

In addition, they'll sing the national anthem at Griz football games and Osprey baseball games. Barring occurrences like this year's flu season, they'll perform in retirement communities.

Peterson's pushed for more visibility in the city.

After all, that's what can spur membership – and keep the club going for the next 70 years.