Question: Planet X is an instrumental rock supergroup, founded by keyboardist Derek Sherinian and who else?

Context articles: Planet X (band)
Black Country Communion
Brett Garsed
Oceana (album)
Black Country Communion discography
Inertia (Derek Sherinian album)
Planet X (Derek Sherinian album)
Sons of Apollo
Derek Sherinian
Universe (Planet X album)

Planet X is an instrumental rock supergroup, founded by keyboardist Derek Sherinian and drummer Virgil Donati.
 Throughout more than a decade of activity, they have released three studio albums and a live album, each with a variety of guest musicians and oft-changing lineups.
Black Country Communion is an English-American hard rock band based in Los Angeles, California.
 Formed in 2009, the band is a supergroup composed of bassist and vocalist Glenn Hughes, guitarist and vocalist Joe Bonamassa, drummer and backing vocalist Jason Bonham, and keyboardist Derek Sherinian.
 Originally formed by Hughes and Bonamassa with the help of producer Kevin Shirley, the group released its self-titled debut album in September 2010.
 Second album "Black Country Communion 2" followed in June 2011, which was promoted on a European tour later in the year.
 The band released its third album "Afterglow" in October 2012.
Brett Edward Garsed (born 20 April 1963) is an Australian musician and songwriter, best known for his work as a guitarist with John Farnham and T. J. Helmerich, as well as being a former member of the American band Nelson.
 Garsed was featured on Derek Sherinian's solo records "Planet X" (1999) and Planet X's "Quantum" (2007), and more recently Sherinian's "Molecular Heinosity" (2010).
Oceana is the seventh studio album by keyboardist Derek Sherinian, released on September 5, 2011 through Music Theories Recordings.
 After his recording sessions for the album, guitarist Joe Bonamassa posted on his official forum: "This session was one of the most challenging of my career.
 To be in the studio with Derek Sherinian and Simon Phillips [is] daunting.
 A huge thanks to Both Derek and Simon for getting me through it.
 I learned a lot.
 "Oceana" is a killer record.
 Highly recommended."
The discography of Black Country Communion, an English-American hard rock band, consists of four studio albums, one live album, one single, one video album and seven music videos. Formed in Los Angeles, California in 2009, Black Country Communion is a supergroup composed of bassist and vocalist Glenn Hughes, guitarist and vocalist Joe Bonamassa, drummer Jason Bonham and keyboardist Derek Sherinian.
 Working with producer Kevin Shirley, the band released its self-titled debut album through J&R Adventures and Mascot Records in September 2010.
 The album reached number 54 on the "Billboard" 200, number 13 on the UK Albums Chart, the top 20 of the US "Billboard" Hard Rock Albums and Top Rock Albums charts, and topped the UK Rock & Metal Albums Chart.
Inertia is the second studio album by keyboardist Derek Sherinian, released in 2001 through InsideOut Music.
 This album marks the beginning of Sherinian's longtime collaborations with drummer Simon Phillips as well as guitarists Steve Lukather and Zakk Wylde.
Planet X is the first studio album by keyboardist Derek Sherinian, released in 1999 through Magna Carta Records.
 The album was devised after Sherinian left progressive metal band Dream Theater in January 1999.
 He then joined drummer Virgil Donati in forming a band also named Planet X, which released their own first album "Universe" in 2000.
 Guitarist Brett Garsed, who plays on "Planet X", would later return on the band Planet X's album "Quantum" in 2007.
Sons of Apollo is an American progressive metal supergroup formed in 2017 and composed of Mike Portnoy, Billy Sheehan, Derek Sherinian, Jeff Scott Soto and Ron "Bumblefoot" Thal.
 Portnoy, Sheehan and Sherinian had already worked together at a short-lived, live instrumental project with Tony MacAlpine.
 Sherinian was asking Portnoy to be a drummer in a band full-time.
 Portnoy agreed when he had time for it.
Derek Sherinian (born August 25, 1966) is an American keyboardist who has toured and recorded for Alice Cooper, Billy Idol, Yngwie Malmsteen, Kiss, Steve Vai, and Joe Bonamassa.
 He was also a member of Dream Theater from 1994–99, is the founder of Planet X and also one of the founding members of Black Country Communion and Sons of Apollo.
 He has released seven solo albums that have featured a variety of prominent guest musicians, including guitarists Slash, Yngwie Malmsteen, Allan Holdsworth, Steve Lukather, Joe Bonamassa, Billy Sheehan, Zakk Wylde and Al Di Meola.
Universe is the first studio album by instrumental rock/progressive metal supergroup Planet X, released on June 6, 2000 through Inside Out Music.
 The album is essentially a continuation of keyboardist Derek Sherinian's 1999 debut solo release "Planet X", but this time as a full band effort featuring guitarist Tony MacAlpine and drummer Virgil Donati.