Question: Sharon Osbourne's management company represents which American frontman?

Context paragraphs:
Aimee Osbourne: Aimee Rachel Osbourne (born 2 September 1983) is an English-American actress and musician.  She is the eldest daughter of Ozzy and Sharon Osbourne.  While her siblings Jack and Kelly achieved pop culture fame for appearing in the family's MTV reality series "The Osbournes", the more private Aimee declined to appear on the show, feeling that doing so would typecast her and affect her musical career.  She has expressed discomfort with some of her parents' behavior on television.

Rock of Love: Charm School: Rock of Love: Charm School, known as Sharon Osbourne' s Charm School in the UK, and as Charm School: Rock of Love Girls in Germany, is the second season of the VH1 reality television series "Charm School".  Fourteen contestants from both seasons of "Rock of Love with Bret Michaels" are competing to develop proper etiquette in order to win $100,000.  Sharon Osbourne is the host.  "Rock of Love: Charm School" first aired on VH1 on October 12, 2008.  Brandi Mahon was ultimately named "Charm School Queen" and was awarded the $100,000.

Mama, I'm Coming Home: "Mama, I'm Coming Home" is the third song on the 1991 album "No More Tears" by the English heavy metal singer Ozzy Osbourne.  Sharon Osbourne has previously claimed that the song was written by Ozzy in tribute to her, however, the song was actually co-written by Lemmy Kilmister, Zakk Wylde (Osbourne's long-time guitarist) and multi-platinum producer/engineer Tom Fletcher.  Lemmy was brought in as a songwriter for the "No More Tears" album, providing lyrics for the tracks "Mama I'm Coming Home" , "Hellraiser", "Desire", and "I Don't Want to Change the World."

Sharon Osbourne Management: Sharon Osbourne Management is a talent management company set up by Sharon Osbourne that manages acts in the entertainment industry.  Though mostly music acts, it has guided the careers of husband Ozzy Osbourne, children Kelly Osbourne and Jack Osbourne, as well as The Smashing Pumpkins, Coal Chamber, Queen, Gary Moore, Motörhead, Lita Ford, and ELO.

Opus 3 Artists: Opus 3 Artists is an independent artists management firm with offices in New York City, Los Angeles and Berlin and represents several classical artists, as well as artists in the non-classical genres, such as jazz, world music, theater, dance, and special attractions.  Formerly the classical music division of International Creative Management (ICM), Opus 3 Artists was created in 2006.  The organization was started by Sol Hurok, whose Hurok Concerts began in the 1920s and lasted through the 1970s.  In 1976 the former president of the company started his own firm, ICM Artists Ltd., taking with it several Hurok clients.  The company separated from ICM in 2006 as "Opus 3 Artist"s. David V. Foster is currently President and CEO of Opus 3 Artists.  The company represents several notable artists and groups, including Yo-Yo Ma, Gil Shaham, Krystian Zimerman, and Alvin Ailey American Dance Theater.

Ozzfest: Ozzfest is an annual festival tour of the United States and sometimes Europe (and for the first time Japan in 2013) featuring performances by many heavy metal and hard rock musical groups.  It was founded by Ozzy Osbourne and his wife Sharon Osbourne, both of whom also organise each yearly tour with their son Jack Osbourne.  The Ozzfest tour has featured bands of a variety of genres within heavy metal and hard rock, including alternative metal, thrash metal, industrial metal, metalcore, hardcore punk, deathcore, nu metal, death metal, post-hardcore, gothic metal and black metal.  Ozzy Osbourne and Black Sabbath have played the tour several times over the years.

Diary of a Madman Tour: The Diary of a Madman Tour was the second concert tour by English heavy metal vocalist Ozzy Osbourne.  It was undertaken in support of Osbourne's second album "Diary of a Madman" and covered Europe, North America, and Asia.  This was Rhoads's last tour as he died in a plane crash at a small airport in Leesburg, Florida, on March 19, 1982, during the first leg of the tour.  The band took a two-week break after his death.  Ozzy and Sharon Osbourne restarted the tour with ex-Gillan guitarist Bernie Tormé, who only performed a couple of shows before being replaced by future Night Ranger guitarist, Brad Gillis.

America's Got Talent (season 7): Season seven of "America's Got Talent", a reality television series, premiered on May 14, 2012.  Sharon Osbourne and Howie Mandel returned as judges.  Judge Piers Morgan left the show after season six and was replaced by radio personality Howard Stern, as announced on his Sirius XM radio show on December 15, 2011.  Because of Stern's commitments to his radio program, the live (post-Las Vegas) episodes moved from Los Angeles to the New Jersey Performing Arts Center in Newark, New Jersey.  The season ended on September 13, 2012, with Olate Dogs announced as the winners of the season.  This was Sharon Osbourne's final season.

The Smashing Pumpkins: The Smashing Pumpkins are an American alternative rock band from Chicago, Illinois, formed in 1988.  Formed by frontman Billy Corgan (lead vocals, guitar) and James Iha (guitar), the band included D'arcy Wretzky (bass guitar) and Jimmy Chamberlin (drums) in its original incarnation.  It has undergone many line-up changes over the course of its existence, with the current lineup being Corgan and rhythm guitarist Jeff Schroeder.

The Sharon Osbourne Show: The Sharon Osbourne Show refers to either of two TV chat shows hosted by Sharon Osbourne – the original US version, or the more recent UK (ITV) version.  These are described separately below.

Supporting paragraphs: Sharon Osbourne Management The Smashing Pumpkins
Answer: Billy Corgan