Brad Delp, 55; lead singer for hugely popular ‘70s rock ‘n’ roll band Boston

Brad Delp, 55, the lead singer for Boston, a huge rock sensation in the 1970s, was found dead Friday in his home in Atkinson, N.H., police said.

Police Lt. William Baldwin said the death was “untimely” and that there was no indication of foul play. The cause remained under investigation by the Atkinson police and the New Hampshire medical examiner’s office.

The band was formed in 1975 by Tom Scholz, a guitarist and keyboardist from Toledo, Ohio, and four musicians from Boston: vocalist and guitarist Delp, guitarist Barry Goudreau, drummer John “Sib” Hashian and bassist Fran Sheehan.

Scholz, a senior product designer for Polaroid who had a master’s degree in mechanical engineering from MIT, had recorded a 12-track demo album in his home recording studio, and the rest of the band helped put the finishing touches on what became their 1976 self-titled debut, “Boston.”

The record, which featured the hit single “More Than a Feeling,” became the best-selling debut album of all time, eventually passing 16 million copies in the United States alone.

The band melded a powerful guitar sound with soaring vocal harmonies and heavy bass and drum backing that precisely fit the popular adult-oriented rock format of the ‘70s.

After an arena tour, they released their second album, “Don’t Look Back,” in 1978, but sales fell short of expectations. It was eight more years before they released another album, “Third Stage,” and band members dropped away during the long stretches between recording. By the time “Walk On” was released in 1994, Scholz was the only remaining original member.

Delp sang on two of Goudreau’s solo records in the ‘80s. They formed RTZ in 1991 and released one album.

Boston had recently re-formed and had last played together in November 2006 at Boston’s Symphony Hall. They were scheduled to tour with REO Speedwagon this year.