Question: What notable pop artist started out his career on adult contemporary radio along with the performer of Illuminations?

Knowledge 1: Illuminations (Josh Groban album)
Illuminations is the fifth studio album by American singer-songwriter Josh Groban, produced by Rick Rubin. Similar to his previous albums, "Illuminations" contains songs sung in a variety of languages, including his first take on a Portuguese song, "Você Existe Em Mim", which Groban co-wrote with Lester Mendez and Carlinhos Brown. The album was released on November 15, 2010. [SEP] Knowledge 2: Adult contemporary music
While most artists became established in other formats before moving to adult contemporary, Michael Bublé and Josh Groban started out as AC artists. Throughout this decade, artists such as Nick Lachey, James Blunt, John Mayer, Bruno Mars, Jason Mraz, Kelly Clarkson, Adele, Clay Aiken and Susan Boyle have become successful thanks to a ballad heavy sound. Much as some hot AC and modern rock artists have crossed over into each other, so too has soft AC crossed with country music in this decade. Country musicians such as Faith Hill, Shania Twain, LeAnn Rimes and Carrie Underwood have had success on both charts.
Knowledge 1: Illuminations (Josh Groban album)
Illuminations is the fifth studio album by American singer-songwriter Josh Groban, produced by Rick Rubin. Similar to his previous albums, "Illuminations" contains songs sung in a variety of languages, including his first take on a Portuguese song, "Você Existe Em Mim", which Groban co-wrote with Lester Mendez and Carlinhos Brown. The album was released on November 15, 2010. [SEP] Knowledge 2: Adult contemporary music
A notable pattern that developed during the 2000s and 2010s has been for certain pop songs to have lengthy runs on AC charts, even after the songs have fallen off the Hot 100. Adrian Moreira, senior vice president for adult music for RCA Music Group, said, "We've seen a fairly tidal shift in what AC will play". Rather than emphasizing older songs, adult contemporary was playing many of the same songs as top 40 and adult top 40, but only after the hits had become established. An article on MTV's website by Corey Moss describes this trend: "In other words, AC stations are where pop songs go to die a very long death. Or, to optimists, to get a second life."
Knowledge 1: Illuminations (Josh Groban album)
Illuminations is the fifth studio album by American singer-songwriter Josh Groban, produced by Rick Rubin. Similar to his previous albums, "Illuminations" contains songs sung in a variety of languages, including his first take on a Portuguese song, "Você Existe Em Mim", which Groban co-wrote with Lester Mendez and Carlinhos Brown. The album was released on November 15, 2010. [SEP] Knowledge 2: Adult contemporary music
AC radio stations may play mainstream music, but they will exclude hip hop, dance tracks, hard rock, and some forms of teen pop, as they are less popular amongst the target demographic of these radio stations, which is intended for an adult audience. AC radio often targets the 25–44 age group, the demographic that has received the most attention from advertisers since the 1960s. A common practice in recent years is that many adult contemporary stations play less newer music because they also give ample airtime to hits of the past, so the de-emphasis on new songs slows the progression of the AC chart.

Answer: Michael Bublé