Angels & Ghosts is the fifth full-length studio album from English electronica production duo Soulsavers, released worldwide by Columbia Records 23 October 2015.
 It is their second collaboration with Dave Gahan, the frontman of Depeche Mode, as guest vocalist and songwriter, this time released under the moniker Dave Gahan & Soulsavers.
Wong Ka-keung (born 13 November 1964), also known as Steve Wong, is a Hong Kong musician, singer and songwriter.
 He is best known as bassist for the rock band Beyond, of which his elder brother Wong Ka Kui is the lead vocalist.
"Kingdom" is a song performed by Depeche Mode's singer Dave Gahan.
 The song was written and produced by Gahan, Andrew Phillpott, and Christian Eigner for Gahan's second solo album "Hourglass" (2007).
 The song was released as the album's first single in October 2007.
 The single version removed the third stanza of the first verse, the instrumental part preceding the second chorus, and most of the bridge at the end.
Beyond was a Hong Kong rock band that formed in 1983.
 The band became prominent in Hong Kong, Taiwan, Japan, Singapore, Malaysia, Mainland China and Overseas Chinese communities.
 The band is widely considered as the most successful and influential Cantonese music group from Hong Kong.
 In 1993, the founder of the group Wong Ka Kui died due to an accident while filming a show at Fuji Television in Tokyo.
 Beyond continued to perform and record after Wong Ka Kui's death.
 In 2005, the remaining members Paul Wong, Wong Ka Keung and Yip Sai Wing decided to pursue their own solo careers, and Beyond officially disbanded.
Rock and Roll (), is a 1993 album by Hong Kong rock band Beyond.
 This was the last album before the band's late vocalist, Wong Ka Kui died after an accident while filming in Japan.
Das Shadow is a band created by Andrew Phillpott, who is known for co-writing with Christian Eigner and Dave Gahan from Depeche Mode.
 Das Shadow started as a production/remix project, remixing for Dave Gahan, Yazoo and Veto.
Yip Sai-wing (born 19 August 1963) is a Hong Kong musician, best known as the drummer and co-founder of the rock band Beyond, formed with the lead vocalist Wong Ka Kui.
Wong Ka-kui (10 June 1962 – 30 June 1993), was a Hong Kong musician, singer and songwriter, best known as the leader and co-founder of the rock band Beyond, for which he was the lead vocalist, rhythm guitarist and main songwriter.
 He won a lot of awards from 1988 onward.
 The band’s hit songs include "Loving You" (1988), "Truly Love You" (1989), "Amani" (1991), "Boundless Oceans, Vast Skies" (1993) etc.
"Saw Something" and "Deeper and Deeper" are songs performed by Depeche Mode's singer Dave Gahan, co-written and co-produced by Gahan, Andrew Phillpott, and Christian Eigner for Gahan's second solo album "Hourglass" (2007).
 The songs were released as a double A-side single on January 14, 2008.
 "Saw Something" features the Red Hot Chili Peppers's ex member John Frusciante's guitar playing.
 The song was used in the trailer of the 2009 film "Obsessed" and the upcoming film "Claustrum".
David "Dave" Gahan ( ; born David Callcott; 9 May 1962) is an English singer-songwriter, best known as the baritone lead singer of the electronic band Depeche Mode since their debut in 1980.
 He is also an accomplished solo artist, releasing albums in 2003 ("Paper Monsters") and 2007 ("Hourglass").

Question: Wong Ka Kui and Dave Gahan are both in what profession?
Answer: singer-songwriter