Though Mangan jokingly described the duo's music as "polka," Katie jumped in with a more suitable explanation.
"We play a lot of acoustic covers of classic rock, country, stuff that's easy to sing along to," Martin said.
They said among their favorite artists or groups to cover are Tom Petty, Fleetwood Mac, Sheryl Crow, The Dixie Chicks, Faith Hill, Van Morrison and Billy Joel. J.R. and Katie also have about 5 original songs that they scatter into their set.
Both sing while Mangan plays the guitar. When he started playing in State College about 17 years ago, Mangan played with a couple of bands, one of which was Space Goop. He then moved on to duos. First there was J.R. and Sharon, then J.R. and Deborah and now, J.R. and Katie. This may leave fans confused. Where have all of J.R.'s women gone?
"It's just circumstantial. People move on to different things. Sharon got married and moved, Deborah moved to L.A.," Mangan said.
J.R. and Katie play not only bars in State College, they also occasionally play weddings, holidays, parties and formals.
"We go wherever the money is green," Mangan said with a laugh.
The duo also plans on recording some of its music as a winter project while students are away for the holidays.
Among the groups' influences, Mangan said he's always loved Neil Young and Tom Petty while Martin is a huge fan of Tina Turner and Faith Hill.
"I just respect people with great voices," Martin said.
Susan Seely of the Rathskeller likes their "classic rock and country" tunes that she said are traditional sing-a-longs, and so does the crowd.
"The crowd responds really well. People just love them," Seely said.
Martin described the duo's performance.
"We just try to be entertaining and make sure people have a great time and take requests," she said.
Mangan agreed.
"Yup, we roll with the crowd's enthusiasm and play whatever they want to hear," he added.