Answer by taking a quote from the following article:

Josh Groban was born in Los Angeles, California, to Lindy (nee Johnston), a school teacher, and Jack Groban, a businessman. Josh's younger brother, Chris, was born on Josh's fourth birthday. Josh's father is a descendant of Jewish immigrants from Poland and Ukraine, and converted from Judaism to Christianity upon marrying Josh's mother. Josh's mother's ancestry includes English, German, and Norwegian.

On February 24, 2002, Groban performed "The Prayer" with Charlotte Church at the closing ceremonies of the Winter Olympics in Salt Lake City, and by November, he had his own PBS special, "Josh Groban In Concert" (2002). In December 2002, he performed "To Where You Are" and sang "The Prayer" in a duet with Sissel Kyrkjebo at the Nobel Peace Prize Concert in Oslo, Norway. He joined The Corrs, Ronan Keating, Sting, Lionel Richie, and others for a Christmas performance at the Vatican in Rome, Italy. In 2003, Groban performed at the David Foster concert for World Children's Day, singing "The Prayer" with Celine Dion and the finale song, "Aren't They All Our Children?" with artists including Yolanda Adams, Nick Carter, Enrique Iglesias, and Celine Dion.  Groban's second album Closer, produced and written by Foster, was released on November 11, 2003. Groban said that he believed that this second album was a better reflection of him, and that his audience would be able to get a better idea of his personality from listening to it.  Two months after Closer was released, it rose on the Billboard charts from number 11 to number one. Groban's cover of "You Raise Me Up" became his third most popular song on the adult contemporary charts as of March 2004. Later that year, he also performed the song "Remember" (with Tanja Tzarovska) on the Troy soundtrack, "Believe" on the soundtrack to the 2004 animated film The Polar Express and a cover of Linkin Park's "My December".  In the summer of 2004, Groban returned to Interlochen, performing and discussing his earlier experiences with local residents and campers. On November 30, 2004, his second live DVD, Live At The Greek, was released; it was also shown as a Great Performances special on PBS. Also in 2004, Groban performed "Remember When It Rained," backed by a full orchestra, at the American Music Awards, where he was nominated for Favorite Male Artist in the pop category; he was also nominated for a People's Choice Award in that year. His recording of "Believe" secured a 2005 Academy Award nomination for the song's two writers, Glen Ballard and Alan Silvestri, and earned them a Grammy in the category Best Song Written for a Motion Picture, Television or Other Visual Media at the ceremony held in February 2006.

What other performances are important?
by November, he had his own PBS special, "Josh Groban In Concert" (2002).