Michael Jackson is in a court in California, US, for a trial where he faces 10 charges of hurting a child.
Mr Jackson arrived at the court dressed all in white and waved at hundreds of fans before entering the building where his trial is taking place.
A jury - who decide if a person is guilty or not - will be chosen from a pool of 750 people over the next month.
Mr Jackson, 46, has denied all the charges. If he is found guilty he could face up to 21 years in prison.
Because Michael Jackson is so famous the court has to be very careful who they choose to make up the people on the jury.
Potential jurors will be given a seven-page questionnaire about the case and told to return next week.
They will then be individually questioned by the judge before 12 jurors and eight reserves are selected to decide if Mr Jackson should be sent to prison.
This process could take between three and six weeks.
Michael Jackson on his website
American court cases are sometimes televised but this one will not be.
Media organisations across the world are getting ready to report on the huge trial, which some people are already calling the "celebrity trial of the century".
On Sunday the multi-million selling singer made an video plea on his website asking for a fair hearing in his trial.
The trial is expected to last for months.