Music continually changes and transforms into new things. The JACK Quartet — John Pickford Richards, Ari Streisfeld, Christopher Otto, and Kevin McFarland — take modern music and puts a new spin on it; the members form a string quartet, which traditionally plays classical music.

The four men, who met at the Eastman School of Music in Rochester, N.Y., will perform at 7:30 p.m. today in the Riverside Recital Hall.

JACK, named for the initials of the four members, has previously performed three times at the University of Iowa, but they feel this performance will be different.

“We’re going to be playing music we’ve never played here before,” said Richards, one of the group’s three violinists. “One of the songs will be on our next album. We’re going to play another piece that we’ll actually perform around the audience.”

Richards said a particularly important guest will attend the performance as well.

“We’re going to play music by Roger Reynolds, and he’s actually going to be here. It’ll be really great to have him here. It always really heightens the experience for us when the composer is here — more magical.”

This is one benefit of the group focusing on new, contemporary music and continually working with new composers.

“With a composer like Beethoven, you can only speculate on what he intended,” said violinist Otto. “With new composers, your performance of their work becomes the beginning of the history of the piece. You actually help shape the interpretation of the piece. It’s a powerful position to be in.”

It is a position the members of the quartet said they are familiar with; playing contemporary compositions pushes them to grow as musicians, they said.

“Often, we work with composers dealing with different kind of playing techniques, extended techniques in which we’re playing our instruments in different ways,” violinist Streisfeld said.

“Mozart, Beethoven, Brahms play their instruments in a particular way, and there’s a certain repertoire, and we all studied this in school — so we work with new composers to understand their technique of playing the instruments.”

These new works have given the group plenty of opportunities for growth over the years since its founding in 2005.

“It’s interesting to see how we’ve grown over the years,” Otto said. “It started out as just friends playing music we loved together and doing summer festivals here and there, but we’ve developed ways, over the years, of learning more music. Our interests have expanded; we’ve discovered more techniques and styles over the years. Our interpretations have changed over the years. We’ve gotten more comfortable and organic — some pieces are becoming second nature, but some are still fresh and exciting.”

Playing a variety of compositions from different eras has influenced JACK’s style.

“Our interests then were mostly on the European modernist style, but now our interests have really broadened to doing many more styles — popular music and music from other parts of the world,” Richards said. “We don’t limit ourselves to one type of style.”

The quartet’s interest in diverse styles has led it all over the world, including Bali for the Bali Arts Festival. The members said the performance was one of their most memorable.

“I think I actually said Bali was my most memorable performance in advance,” said McFarland, the group’s cellist.

“We were dressed in traditional Balian wardrobe from head to toe, and there was choreography for everything we played; it was just a unique experience that none of us will ever forget,” Richards said.

Bali is certainly a standout, but all men agree that each collaboration is unforgettable. A crucial collaboration — their first — was with Helmet Lachnemann.

“We kind of formed to play one of his quartets before we were the JACK Quartet,” McFarland said. “We worked with him at a festival in Mexico and then again in Germany, and now all over the world. He is one of the sweetest and most endearing people we have ever met. He’s like a grandfather to the group. His music brought us together.”

The group has grown since its first collaboration, and it will continue to work with new artists in upcoming years. From this year through 2014, JACK will work with legendary pianist Maurizio Pollini all around the world.

“He is a pianist who has a series of concerts called ‘Perspectives,’ in which he pairs newer works with older works,” Otto said. “It’s a great opportunity for us to play in these great venues. So basically, he’s playing two Beethoven sonatas, and we’re playing Grido.”

JACK will perform Grido in addition to music by California-based composer Reynolds.

“Each movement [selected by Reynolds] is devoted to a different composer who is influential for him,” McFarland said. “We’re going to have a pretty well-rounded program.”