Question: What black-pop changing group has worked with producer Rex Salas?

Context paragraphs:
Best Airlines: Best Airlines was a small airline that flew to a miscellaneous and changing group of cities in the Mid-Atlantic United States in the mid-1980s.  Their headquarters was in the Covington, Kentucky area which is near the Cincinnati-Northern Kentucky International Airport.  The May 15, 1983 timetable indicates headquarters in Florence, KY and the January 7, 1985 timetable indicates headquarters in Ft. Mitchell, KY.

Final Fantasy IV: Final Fantasy IV , also known as Final Fantasy II for its initial North American release, is a role-playing video game developed and published by Square (now Square Enix) for the Super Nintendo Entertainment System.  Released in 1991, it is the fourth main installment of the "Final Fantasy" series.  The game's story follows Cecil, a dark knight, as he tries to prevent the sorcerer Golbez from seizing powerful crystals and destroying the world.  He is joined on this quest by a frequently changing group of allies.  "Final Fantasy IV" introduced innovations that became staples of the "Final Fantasy" series and role-playing games in general.  Its "Active Time Battle" system was used in five subsequent "Final Fantasy" games, and unlike prior games in the series, "IV" gave each character their own unchangeable character class.

Rex Salas: Rex Salas (born March 16, 1962) is an American record producer, songwriter, musical director, and music arranger.  Best known in recent years for his work as the musical director for Janet Jackson on several of her tours, Salas has worked with Vanessa Williams, Justin Timberlake, Cher, Boyz II Men, Robert Palmer, Mariah Carey, Stevie Wonder, Lionel Richie, JC Chasez, Earth, Wind and Fire, will.i.am, Robin Thicke, 50 Cent, Jessica Simpson, Nicole Scherzinger, Taylor Dayne, Lindsay Lohan, Adam Levine, Brandy, Maxwell, Leona Lewis, Brian McKnight, Teddy Pendergrass, The Isley Brothers, The Jacksons, UB40, Jeffrey Osborne, All-4-One, Johnny Gill, George Howard, Gladys Knight, The Gap Band, Lalah Hathaway, Jasmine Guy, Tatyana Ali, James Ingram, Corbin Bleu, Patti Austin, Lakeside, The Mac Band, Klymaxx, Chuckii Booker, The Dazz Band, Chanté Moore, Patrice Rushen, Tease, Atlantic Starr, Lenny Williams, Barbara Weathers, Miki Howard, Rebbie Jackson, Aly & AJ, Joyce Kennedy (Mother’s Finest), Paul Jackson, Jr., Brian Simpson, Vesta Williams, Level 42, Sheena Easton and more.

C. E. Webber: Cecil Edwin Webber (sometimes known by the nickname "Bunny"; 9 April 1909June 1969) was a British television writer and playwright.  He is best remembered for his contribution to the creation of the famous science-fiction series "Doctor Who" while working as a staff writer for the BBC in the early 1960s.  Although none of his scripts were eventually used in the programme—producer Rex Tucker felt he was not capable of 'writing down' to the level required—he participated in many crucial early development meetings, and co-wrote the first format document for the series with Donald Wilson and Sydney Newman.  His draft script for the proposed first ever episode formed the basis of the broadcast first episode eventually written by Anthony Coburn.  Webber received a co-writer's credit on internal BBC documentation for the episode, although not on screen.

Apostolos Andreas Monastery: Apostolos Andreas Monastery (Turkish: "Apostolos Andreas Manastırı" ; Greek: Απόστολος Ανδρέας ) is a monastery situated just south of Cape Apostolos Andreas, the north-easternmost point of the island of Cyprus, in Rizokarpaso in the Karpass Peninsula.  The monastery is dedicated to Saint Andrew and is an important site for the Cypriot Orthodox Church.  It was once known as "the Lourdes of Cyprus", served not by an organized community of monks but by a changing group of volunteer priests and laymen.  Both Greek Cypriot and Turkish Cypriot communities consider the monastery a holy place.  As such it is visited by many people for votive prayers.  The contents of the monastery are also noteworthy.

Earth, Wind &amp; Fire: Earth, Wind & Fire (EWF) is an American band that has spanned the musical genres of R&B, soul, funk, jazz, disco, pop, rock, Latin and African.  They are one of the most successful bands of all time. " Rolling Stone" "Magazine" described them as "innovative, precise yet sensual, calculated yet galvanizing" and declared that the band "changed the sound of black pop".

Bloom (Jeff Coffin album): Bloom was the fourth album released by Jeff Coffin, released in 2005.  This album was the second album recorded and released with the Mu'tet, a constantly changing group of guest musicians that play with Coffin.

Go-Round: Go-Round was the third album released by Jeff Coffin, released in 2001.  This album was the first album recorded and released with the Mu'tet, a constantly changing group of guest musicians that play with Coffin.

Hugh David: Hugh David (17 July 1925 – 11 September 1987) was an actor turned television director.  David was born in Aberystwyth, Wales.  His directorial credits include "Compact", "Z-Cars", "The Pallisers" and "Doctor Who", for which he directed two stories in the Patrick Troughton era.  While still an actor in the early 1960s, he had actually turned down the leading role in "Doctor Who" when it was offered to him by his friend, the producer Rex Tucker.  David later stated that as he had recently starred in the Granada Television series "Knight Errant" and disliked the high public profile it brought him, he was not keen to take on another leading role.  He died in London leaving his widow actress Wendy Williams.

5000 Volts: 5000 Volts is the name of a British disco recording act that achieved success throughout Europe during the 1970s.  The group consisted of vocalists Tina Charles and Martin Jay, with a changing group of session musicians.

Supporting paragraphs: Rex Salas Earth, Wind &amp; Fire
Answer: Earth, Wind & Fire