Question: Are Jon Hume and Marcus Mumford both singers?
Context: Burnt Letters is the second studio album by Australian singer and songwriter Taylor Henderson, released on 11 July 2014 by Sony Music Australia.  The album is Henderson's first to be made up of entirely original songs, as his previous self-titled debut album consisted of cover songs.  Recorded over an eight-month period, Henderson worked on "Burnt Letters" with a variety of producers and writers such as Louis Schoorl, Alex Hope, Hayley Warner, Jon Hume, Robby De Sa and Lindsay Rimes.  Described by the singer as "a very raw and open acoustic album", "Burnt Letters" incorporates styles of pop, folk and country music.  Lyrically, the album's themes speak of "family, lost love and longing for home." Lost on the River: The New Basement Tapes is an album produced by T Bone Burnett featuring a collective of musicians recording under the moniker The New Basement Tapes—Elvis Costello, Rhiannon Giddens, Taylor Goldsmith, Jim James and Marcus Mumford. Dann Hume (born Daniel Benjamin Cobbe, 1 September 1987, Whangaparaoa, New Zealand) is a singer-songwriter and record producer.  Hume is the youngest of three brothers (with Peter Hume and Jon Hume) who make up the alternative rock band, Evermore since 1999. Mumford & Sons are a British band formed in 2007.  The band consists of Marcus Mumford (lead vocals, electric guitar, acoustic guitar, drums), Ben Lovett (vocals, keyboard, piano, synthesizer), Winston Marshall (vocals, electric guitar, banjo) and Ted Dwane (vocals, bass guitar, double bass). One Love Manchester was a benefit concert and British television special held on 4 June 2017, which was organised by American singer Ariana Grande in response to the bombing after her concert at Manchester Arena two weeks earlier.  The concert took place at Old Trafford Cricket Ground in Old Trafford, Greater Manchester, and aired live on BBC One in the UK with hosts Sara Cox and Ore Oduba.  The concert was attended by 50,000 people.  Guest stars included Justin Bieber, the Black Eyed Peas, Coldplay, Miley Cyrus, Marcus Mumford, Niall Horan, Little Mix, Katy Perry, Take That, Imogen Heap, Pharrell Williams, Robbie Williams and Liam Gallagher. Jon Hume (born 6 November 1983) is the lead singer of Evermore.  He is a singer-songwriter, multi-instrumentalist, Record Producer and Studio owner.  Jon is the eldest of the three brothers who make up the New Zealand band Evermore. The New Basement Tapes is an American/British musical supergroup made up of members Jim James, Elvis Costello, Marcus Mumford, Taylor Goldsmith, and Rhiannon Giddens.  The group is best known for "", their 2014 album which consists of tracks based on newly uncovered lyrics handwritten by Bob Dylan in 1967 during the recording of his 1975 album with The Band, "The Basement Tapes".  The group is also featured in the 2014 Showtime documentary "Lost Songs: The Basement Tapes Continued". Marcus Oliver Johnstone Mumford (born 31 January 1987) is a British-American singer, songwriter, musician and producer best known as the lead singer of the band Mumford & Sons.  He also plays a number of instruments with the group, including guitar, drums and mandolin. "Light Surrounding You" is the second single by alternative rock band, Evermore, taken from their second studio album, "Real Life" (June 2006).  It was written by Dann Hume, the group's drummer and lead singer and guitarists Jon Hume.  The record is co-produced by Jon Hume.  The song was released in October 2006 and peaked at No. 15 on the RIANZ Singles Chart in New Zealand and number one on the ARIA Singles Chart, making it Evermore's most successful single in Australia.  It was the first single by a New Zealand artist to top the Australian charts since "How Bizarre" by OMC in 1996. "Winter Winds" is the second single by the London folk quartet Mumford & Sons, released from their debut album, "Sigh No More".  It was released in the UK on 6 December 2009, where it peaked at number 44; in Belgium it reached number 29.  Marcus Mumford has said that this is his favorite song to sing live.  It was written by Winston Marshall.
Answer: lead singer