Ian Watkins, the former lead singer of Lostprophets, has been sentenced to 35 years after been found guilty of a string of child sex offences, including attempting to rape a baby.
Watkins, 36, of Pontypridd, pleaded guilty to 13 sex offences on the opening day of his trial at Cardiff Crown Court in November.
The judge said how Watkins showed "evident delight" in abusing children and had shown "an almost complete lack of remorse" for his actions. Watkins was sentenced to 29 years in jail, followed by six years on licence.
He was told will have to serve two thirds of his 29-year sentence before he can be considered for release.
Watkins appeared in court along with two female co-accused, known only as Woman A and Woman B. They also pleaded guilty to charges including sexually assaulting a child aged under 13 years and taking and distributing indecent photographs of children.
Upon sentencing, Judge Justice Royce told all three the crimes they had committed "plumbed new depths of depravity".
He added: "Those who have appeared in these courts over many years see here a large number of horrific cases. This case breaks new ground.
"Any decent person looking at or listening to material here would experience shock, revulsion, anger and incredulity."
Royce added to Watkins: "I am satisfied that you are a deeply corrupting influence. You are highly manipulative.
"You are a sexual predator. You are dangerous. The public, and in particular young females and children, need protection from you."
He described the plan Watkins had with Woman A to film the singer assaulting her son was both "sickening and incomprehensible" and how texts exchanged between Watkins and Woman B discussing how he would abuse her daughter "defy belief".
Woman A was sentenced to 14 years in jail. Woman B was sentenced to a total of 17 years.
Watkins, who was described as a "determined and committed paedophile" in court, admitted conspiring to rape a child, three counts of sexual assault involving children, seven involving taking, making or possessing indecent images of children and one of possessing an extreme pornographic image involving a sex act on an animal.
The charges include including attempting to rape a child, sexually assaulting a child under 13 and aiding and abetting a female co-defendant to sexually assault a child under 13.
During sentencing, the court heard how after pleading guilty in November, Watkins made a phone call from Parc prison in Bridgend. In one call, he told the unnamed woman he would release a statement saying "I'm going to put a statement on the 18th now just to say it was megalolz, I don't know what everyone is getting so freaked out about."
Police described the case against all three as the "most shocking and harrowing child abuse evidence" they had ever seen.
Suzanne Thomas, Senior Crown Prosecutor, CPS Wales, said: "These three defendants conspired to commit appalling crimes of abuse against young and defenceless victims.
"The prosecution case was that Ian Watkins was the ringleader of this terrible conspiracy and it is right that his sentence reflects this. He is a highly dangerous and manipulative individual who preyed on his victims in a calculated manner.
"The other two defendants were active participants in the most shocking abuse of their own children. They too have received sentences that reflect their admissions of guilt for these offences."
Alun Michael, Police and Crime Commissioner for South Wales, said the case had exposed a "level of depravity and abuse that is beyond the comprehension of most people".
Det chief insp Peter Doyle, of South Wales Police, said: "The sentences reflects the gravity of the crimes that have been committed. The three paedophiles responsible for the terrible abuse of two babies have now been brought to justice."
Doyle added he is "sure" investigations will show Watkins had more child victims, including some in other countries.
He told BBC Radio 5 Live: "The investigation is very large-scale. It is ongoing and we've got lines of inquiry currently being followed in the United States and Germany and as we go over the investigation I'm sure there will be further victims."
Following his guilty plea, the Independent Police Complaints Commission (IPCC) said they will be investigating South Wales, South Yorkshire and Bedfordshire Police in connection with their handling of allegations Watkins was abusing children years before he was arrested.
The police watchdog said they will be looking into reports allegation about the Watkins were made to them between 2008 and 2012.