Band members were faced with a big decision when they graduated in 1976: Were they going to be a rock band or were they going to sing about Christ?
In a business loaded with hardship and rejection, singing about Christ seemed to be the only thing that was worth doing, Nalle said.
GLAD - the name is not an acronym but the result of a poll taken by band members at a mall in the early '70s - has been performing and recording for more than 20 years.
Has the market for contemporary Christian music changed since the group's beginnings?
"There wasn't any market back then," Nalle said.
He says band members scraped by, in one year performing 250 concerts. But Nalle says they didn't consider what they were doing a hardship.
GLAD has recorded 18 albums since 1978.
The group stepped out of the contemporary Christian genre with the 1995 recording, "A Cappella Gershwin."
The album aims for the heart, celebrating the timeless genius of George and Ira Gershwin. In a press release, Nalle defends the departure by saying the Gershwin tunes are romantic; he and his wife are romantic, and that's healthy and right. The Gershwins' work is a testimony to the talents that come from God, Nalle said.
He recently had a phone call from a woman in Italy, the wife of a choir director who wanted to buy the studio charts - the arrangements - of GLAD'S Gershwin music.
"I think it's great when somebody else does your stuff," Nalle said.
GLAD has sold more than a million records and performed more than 1,000 concerts.
Group members are able to devote themselves to their music full time.
Keyboard player Don Pardoe is single, but all the others are married with at least a couple of kids, so they don't like to be away from their Purcellville, Va., headquarters too frequently or for long periods of time. Touring is limited to about 60 dates a year all over the country, and sometimes in Great Britain and Canada.
Nalle said he feels blessed to be able to make a living doing something he enjoys, something in which he believes.
"I consider what we do to be a privilege," he said.
Something else in which he believes, something else for which GLAD works, is Compassion International, a child development organization that sponsors children in 21 countries.
Eleven years ago, members of GLAD were asked to go to Haiti. Their response was "Why?" Nalle said.
He lives in an upper middle class area, and, until his trip, he had no idea of the poverty that exists in other parts of the world.
Nalle said GLAD has recruited 7,500 sponsors for Compassion International.
The organization aids about 230,000 kids and has GLAD's support because it does such a good job with the money. Eighty-five percent goes to work in the field, Nalle says.
Members of the group also travel to visit children in Third World countries every other year.
"We had to do something," he said.
GLAD's Internet address is http://www.GLAD-pro.com.