Two groups with divergent but complementary styles join forces this weekend.

Between Measures, a newly formed barbershop quartet, and 7 Days, the University’s a cappella choir, appear Saturday at Ted Mann Concert Hall.

7 Days was formed in the fall of 2003, and the 16 members (including Daily reporter Anna Weggel) focus primarily on pop and R&B music. The group’s repertoire includes everything from Aretha Franklin and Earth, Wind & Fire to Justin Timberlake and Billy Joel.

Compare that to the old-fashioned sounds of Between Measures, and the result is a marvelous mix that doesn’t even require a back-up band.

Between Measures was created last semester, and the quartet is now registering to become a student group.

“The name is a double entendre,” said Andrew Berkowitz, one of the three original members. “We’re all majoring in something that involves measuring, and the music we sing is literally between the measures.”

Unlike the music performed by 7 Days, the music of Between Measures has already been written and arranged. But even with an edge like that, the quartet still practices twice a week.

Berkowitz, a math sophomore, is joined by Andrew Smude, an aerospace engineering student, architecture student Hank Butitta and physics student Andrew Ringham.

“We all just love to sing,” Berkowitz said, “and this is our first actual concert.”

The group first performed at Balls, a midnight cabaret show at the Southern Theater. Then, for a small fee on Valentine’s Day, the quartet surprised people with a song and a flower from a sweetheart.

“But other than that,” Berkowitz said, “we’ll just give impromptu recitals for our friends after a rehearsal if we want to try out a new song or just show off a little.”

The group agreed people generally enjoy being serenaded by a barbershop quartet.

“It’s based on traditional harmonies that have an enjoyable and pleasing sound, but we don’t get to hear it that much anymore,” Berkowitz said.

The three original members – Ringham, Berkowitz and Butitta – had a few lead singers until they recruited Smude at the end of last semester.

Barbershop songs are sung a cappella, but the group uses a piano to learn individual parts. The majority of rehearsal time is spent trying to blend combinations of the four parts, because the matching sound production produces the “ring” that’s essential to a barbershop quartet.

“Most people really enjoy it,” Berkowitz said. “I have yet to have someone tell us we aren’t good, except for the other guys in the quartet.”

While neither 7 Days nor Between Measures needs accompaniment, the similarities end there. The R&B/pop style of 7 Days and the mellow, old-fashioned one of Between Measures are different in both sound and style. Between Measures creates harmonies with four parts, while 7 Days has eight parts and vocal percussion.

The styles of the two choirs don’t clash. They complement each other and give the audience a little bit of old-time music, and a little bit of everything else.