A panel of 22 potential jurors has been picked from a pool of 72 people and will form the jury at the trial at Cardiff Crown Court in South Wales.
Judge Justice Royce began today by warning the group that their involvement in the trial would necessitate watching some "very graphic material".
He concluded with the question: "Are you a fan of the group called Lostprophets?"
Watkins, 36, from Pontypridd, former lead singer with Lostprophets, is accused of two separate counts of baby rape.
He is also charged with conspiracy to rape another child, one count of sexual assault, one of aiding and abetting sexual assault by penetration and conspiracy to sexually assault a child.
In addition he faces 17 counts of making, taking and possessing indecent images and one of possessing extreme pornographic image involving an animal.
He denies all 24 charges.
Two women, who cannot be named for legal reasons, also face sexual offence accusations as part of the case.
The three defendants, who will be standing trial together, face a total of 32 charges.
Watkins appeared in court today smartly dressed in a charcoal-coloured three-piece suit. He was clean-shaven but looked heavier and appeared to be going grey.
All the potential jurors were asked today whether they knew or had links with up to two dozen prosecution witnesses or any locations which will figure in the trial.
Justice Royce then went on to warn: "Often members of the jury have to listen to or view evidence which is very distressing or unpleasant. This is irrespective of the guilt or innocence of the defendant.
"This case involves allegations of sexual abuse of very young children and will involve the viewing of very graphic material."
He added: "This case is to be tried on the evidence you will hear in court. It is very important that you do not carry out any of your own research."
He also issued a "very serious warning" to potential jurors not to look up details about any of the defendants on the internet.
Those who ignored the warning would face prosecution, he said.
Before adjourning for the day, he said the trial is scheduled to conclude by December 20, when court finishes for Christmas. If it runs over into the new year, proceedings will resume on January 6.
Of the jury panel of 22 people chosen today, a further six will be retained for an extra day in case they are needed.
Last month the remaining members of rock act Lostprophets, who have sold around 3.5 million records since their formation in 1997, announced that the band had split up.