Thursday's admission in a Provo courtroom means that Keith Brown, 55, will go to prison for at least 10 years.
None of the sisters were in court, but a statement issued to The Associated Press by group spokesman Kimball Thomson said they were satisfied with the plea agreement.
"While clearly the current events surrounding the family are painful, the sisters were well prepared for this day, and are relieved and grateful to close this chapter in their lives," Kimball said.
Brown's three daughters and two sons are part of the classical piano group The 5 Browns, whose albums have topped the classical music charts and who have appeared on "Oprah" and other shows. The group also has been profiled by "60 Minutes."
Brown appeared in Fourth District Count with scratches and bruises on his face but with few other signs of the horrific crash three days earlier in which his Porsche plunged 300 feet into a canyon, also injuring his wife.