Anyone who can't sing along to "Joy to the World," the saga of Jeremiah the Bullfrog, hasn't been listening to the radio much in the past two decades. That song, released in 1971, is the signature number of Three Dog Night.

Three Dog Night will provide two Labor Day shows Sept. 5 at Lagoon, starting at 5 and 8 p.m. Admission is free with an all-day ride pass or $14.95 at the gate (the same price as the all-day ride pass).Founding members Cory Wells and Danny Hutton provide the lead vocals for a show that draws a multi-generational crowd everywhere they go. Original keyboardist Jimmy Greenspan will be joined by Paul Kingery (vocals and guitar), Scott Manzo (bass) and Mike Keeley (drums), who joined the group when it reformed in 1981 after a six-year break.

During the '70s, Three Dog Night toured extensively, breaking all attendance records in a mixture of venues that included concert halls and stadiums. But in '75, according to Wells, "We became disenchanted. We just quietly backed out of the picture. We always had a sort of verbal agreement that we were never going to exploit the public for our own gain. We were not going to do four or five `farewell tours' just to rake in the money. We had come on the scene quietly and we were going to leave the same way, with dignity."

Fortunately for their fans, they each began to miss the music world. When unfinished business brought them back together, they discovered they were ready to try it all over again.

Hutton said they had a "test rehearsal" and discovered that the "old magic was still there."

Three Dog Night was back. The Lagoon concert comes near the end of an arduous, extensive cross-country tour that began in April.