Question: Are Naser Mestarihi and Justin Sane both singer-songwriters?

full_context: Document 1: Tim McIlrath: Timothy James "Tim" McIlrath (born November 3, 1978) is an American punk rock musician. He is the lead singer, rhythm guitarist, songwriter and co-founder of the American punk rock band Rise Against. McIlrath is known to support animal rights and actively promotes PETA with his band. He is also straight edge.
Document 2: Matt Nasir: Matt Nasir is a multi-instrumental musician based in London, England. He currently plays Keyboards in Frank Turner's band The Sleeping Souls and is a member of the London-based rock band 'The Pressure Room'. He has also previously played in Andy Yorke's live band and is known as the 'Archivist' for his remixing work. Frank Turner and The Sleeping Souls headlined Wembley Arena in April 2012 and played at the Opening Ceremony of the 2012 Olympic Games in London. Matt also features as the guitarist in a side-project, Möngöl Hörde, with Frank Turner and Frank's former Million Dead band mate, Ben Dawson. Matt plays a baritone guitar in Möngöl Hörde.
Document 3: 1987 (Naser Mestarihi album): 1987 is the full-length debut of Doha/Dubai based hard rock singer-songwriter Naser Mestarihi. The album was released on June 17, 2013.
Document 4: Naser Mestarihi EP: Naser Mestarihi EP is the eponymous debut EP of Doha based hard rock guitarist Naser Mestarihi. The release of the album marked the first official release of a rock album out of Qatar. All the lyrics and music on the album were written by Mestarihi, who also plays all the instruments with the exception of the drums.
Document 5: Naser Mestarihi: Naser Mestarihi (Arabic: ناصر شاهر صالح المستريحي; born 14 October 1987) is a Qatari born Jordanian-Pakistani singer-songwriter and multi-instrumentalist (guitars, bass & vocals) who is based out of Doha, Qatar and Dubai, United Arab Emirates. Naser is the first rock musician to ever officially release a rock album out of Qatar, the "Naser Mestarihi EP". He released his second album "1987" on 17 June 2013.
Document 6: Nas: Nasir Bin Olu Dara Jones ( ; born September 14, 1973), better known by his stage name Nas , is an American hip hop recording artist, record producer, actor and entrepreneur. The son of Olu Dara, Nas has released eight consecutive platinum and multi-platinum albums and has sold over 25 million records worldwide. He is also an entrepreneur through his own record label; he serves as associate publisher of "Mass Appeal" magazine and is the owner of a Fila sneaker store. He is currently signed to Mass Appeal.
Document 7: Fateh Ali Khan (Qawwali singer): Fateh Ali Khan (Urdu: فتح علی خان) was a classical singer and a Qawwali musician in the 1940s and 1950s. He was born in Jalandhar, Punjab, British India in 1901. Fateh Ali Khan was the father of Pakistani Qawwali musicians, Nusrat Fateh Ali Khan and Farrukh Fateh Ali Khan. Their family has an unbroken tradition of Qawwali, linked closely to the Sufi Chishti Order for over 600 years. Fateh Ali Khan was trained in classical music and Qawwali by his father, "Maula Baksh Khan", and he, soon after his training, distinguished himself as a skilled vocalist and instrumentalist. He learned to play traditional Indian instruments such as sitar, sarod and vichitraveena as well as Western instruments like the violin. He also mastered thousands of verses in Punjabi, Urdu, Arabic and Persian.
Document 8: Joe Jewell: "Joe Jewell is the Dublin-born lead guitarist of Irish band Aslan. His career of over twenty-five years has been characterized by numerous successes on the Irish charts. He co-wrote many of the band's finest songs including "Crazy World", "This Is", "Where's The Sun?", "Hurt Sometimes" to name but a few. He also wrote the memorable riffs behind the songs and is the falsetto backing vocalist behind Christy Dignam in the band. He was also in The Precious Stones during the band's split and sang vocals most notably on "Jesus Says He Loves Me" which was originally intended to be on Aslan's original second album.
Document 9: Hussain Faisal: Hussain Faisal is an Islamic professional reciter, music producer and composer from the Bahrain. He was born in the city of Bani Jamra, Bahrain where he grew up with his 2 brothers and 2 sisters until his late twenties. At that time, he studied and finished his high school then went to the University of Bahrain where he received his bachelor degree in BIS (Business Information Systems). Then he started his Music Production and arrangement career focusing on the Islamic music productions mainly and Arabic in general with some vocal coaching from time to time. He started his Islamic professional singing (reciting) career at the Early 2000's. In 2014, in the month of Muharram, his album (Ard Anishdak) gained multiple millions of views to his video clips on his YouTube channel. He is one of very few Islamic singers whose YouTube channels have been legitimately "Verified" by The YouTube Copyright community and his copyrights are managed by Bint-Alhuda media company in Lebanon. He's well known for his recent 3 Albums and his songs (latmiyat) had a fair opportunity to be viewed on various Islamic TV Channels and aired on few Islamic radio broadcasts as well. He has recited in Bahrain, Oman, Saudi Arabia, Iraq, London, Lebanon and Iran.
Document 10: Billie Joe Armstrong: Billie Joe Armstrong (born February 17, 1972) is an American musician, singer, songwriter and actor who is best known as the lead vocalist, primary songwriter, and guitarist of the punk rock band Green Day, which he co-founded with Mike Dirnt. He is also a guitarist and vocalist for the punk rock band Pinhead Gunpowder and provides lead vocals for Green Day's side projects Foxboro Hot Tubs and The Network.
Document 11: Justin Sane: Justin Cathal Geever, known professionally as Justin Sane, is the lead guitarist and singer/songwriter of the United States-based musical group Anti-Flag, a punk rock band formed in 1988 in Pittsburgh, Pennsylvania known for its outspoken left-wing views. He holds dual US and Irish citizenship and lives in Pittsburgh. His stage name was bestowed upon him by friends in Pittsburgh's punk scene.
Document 12: Life, Love and the Pursuit of Justice: Life, Love, and the Pursuit of Justice is the first solo album by Justin Sane, lead singer of the punk rock band Anti-Flag. The album is entirely his own work, featuring his vocal and guitar work and demonstrating obvious influence from Billy Bragg's earlier recordings. The album is about, exactly as the title simply states, life, love, and justice.
Document 13: Justin Bastard Sane: Justin Bastard Sane (aka Justin Sane) is an American comic book creator, film director, puppeteer and animator. His comic books are done in a silhouette style reminiscent of early film and his movies feature sex, violence and satirical comedy.
Document 14: Anti-Flag: Anti-Flag are an American  pop punk  band from Pittsburgh, Pennsylvania, United States. The band is well known for politically charged lyrics and activism, focusing on anti-war activism, anti-imperialism, class struggle, human rights, and various sociopolitical sentiments. The line-up includes singer/guitarist Justin Sane and drummer Pat Thetic, who founded the band; later members are guitarist Chris Head, and singer/bassist Chris Barker (#2) who replaced Jamie "Cock" Towns, who had replaced original bassist Andy Flag in 1997 following his departure one year prior. Anti-Flag is known also for their advocacy of progressive political action groups such as Greenpeace and Amnesty International. Most recently, the band has declared solidarity with the global Occupy Together movement.
Document 15: A New Kind of Army: A New Kind of Army is a punk rock album originally released by Anti-Flag on May 25, 1999. It was reissued by A-F Records on October 19, 2004 and is also the only album to feature only Justin Sane as lead vocalist. All other albums featured at least one song sung by either Andy Flag or Chris #2.
ground_truth: yes