Question: Are Bruce Dickinson and Robin Zander both leader singers of a band?

full_context: Document 1: I've Always Got You: "I've Always Got You" is a single by American vocalist Robin Zander, best known as lead vocalist for the American rock band Cheap Trick. The single was released in 1993 as the lead single from Zander's debut solo album "Robin Zander". The song was written by Mike Campbell of Tom Petty and the Heartbreakers fame, Zander and J.D. Souther.
Document 2: Paul Di'Anno: Paul Andrews (born 17 May 1958), better known by his stage name Paul Di'Anno, is a British singer best known as the first vocalist to record with heavy metal band Iron Maiden, from 1978 to 1981.
Document 3: Rob Halford: Robert John Arthur Halford (born 25 August 1951) is an English singer and songwriter, who is best known as the lead vocalist for the Grammy Award-winning heavy metal band Judas Priest and famed for his powerful wide-ranging voice. AllMusic says of Halford: "There have been few vocalists in the history of heavy metal whose singing style has been as influential and instantly recognizable", possessing a voice which is "able to effortlessly alternate between a throaty growl and an ear-splitting falsetto". Halford was voted number 33 in the greatest voices in rock by Planet Rock listeners in 2009. In addition to his work with Judas Priest, he has been involved with several side projects, including Fight, 2wo and Halford. In 1998, he came out as gay in an interview with MTV News.
Document 4: Kevin Cronin: Kevin Patrick Cronin (born October 6, 1951) is the lead vocalist, rhythm guitarist, and occasional pianist for the American rock band, REO Speedwagon. REO Speedwagon had several hits on the "Billboard" Hot 100 throughout the 1980s, including two chart-toppers written by Cronin: "Keep on Loving You" (1981) and "Can't Fight This Feeling" (1985).
Document 5: Randy Jackson (Zebra): Randy Jackson (born February 28, 1955) is an American rock musician from New Orleans, Louisiana, best known for his role as frontman for the band Zebra. He was born and raised in New Orleans, Louisiana, United States. In addition to his career with Zebra, he is a Long Island Music Hall of Fame inductee, a Louisiana Music Hall of Fame inductee, and has toured with Jefferson Airplane and tributes to Led Zeppelin, Pink Floyd and The Doors.
Document 6: Robin Zander: Robin Zander (born January 23, 1953) is the lead singer and rhythm guitarist for the rock band Cheap Trick.
Document 7: Bruce Dickinson: Paul Bruce Dickinson (born 7 August 1958), known professionally as Bruce Dickinson, is an English singer, songwriter, musician, airline pilot, entrepreneur, author and broadcaster. He is the lead singer of the heavy metal band Iron Maiden and is renowned for his wide-ranging operatic vocal style and energetic stage presence.
Document 8: Rob Dickinson: Rob Dickinson (born 23 July 1965) is a British musician and singer-songwriter previously of the band Catherine Wheel. Dickinson was raised in Norfolk, England, and is the paternal cousin of Iron Maiden frontman Bruce Dickinson. He is now a solo artist and the founder and creative director of Singer Vehicle Design, which performs restoration and modification of client vehicles.
Document 9: Robin Zander (album): Robin Zander is the debut solo album from American singer Robin Zander of Cheap Trick. It was released in 1993 by Interscope Records.
Document 10: Born in '58: "Born in '58" is the last single from Bruce Dickinson's debut solo album, "Tattooed Millionaire", released on March 25 1991. The song is about Bruce Dickinson's early life, growing up with his Grandparents in Worksop (Dickinson was born in 1958).
Document 11: Paul Day (musician): Paul Mario Day (born 19 April 1956, Whitechapel, East London) is a British singer who is well-known as the original lead vocalist of Iron Maiden from 1975 to 1976.
Document 12: Mark Farner: Mark Fredrick Farner (born September 29, 1948) is an American singer, guitarist and songwriter, best known as the lead singer and lead guitarist for Grand Funk Railroad, and later as a contemporary Christian musician.
Document 13: Bruce Dickinson discography: Bruce Dickinson, a British heavy metal singer, has released six studio albums, two live albums, one compilations, ten singles, three video albums, fourteen music videos, and one box set. In 1979, after playing in local groups, Dickinson joined hard rock band Samson. He departed after two years to become Iron Maiden's lead vocalist. His debut with this band is considered a "masterpiece", which was followed with a series of top-ten releases. In 1989, while Iron Maiden were taking a year off, Dickinson and former Gillan guitarist, Janick Gers, composed a song for . His solo debut, "Tattooed Millionaire" (1990), was an effort that favoured a hard rock/pop metal approach, different from what fans assumed would be an aggressive, Iron Maiden-like album. Four songs—the title track, "Dive! Dive! Dive!", "Born in '58", and a cover version of David Bowie's "All the Young Dudes"—were released as singles. Dickinson returned to Iron Maiden, accompanied by Gers as the new guitarist, and the project went on hiatus. "Dive! Dive! Live!" was a live video recorded from a concert in Los Angeles, California, in August 1990, and released in July 1991.
Document 14: Next Position Please: Next Position Please is the seventh studio album by American rock band Cheap Trick, produced by Todd Rundgren and released in 1983. The title track was originally demoed for the band's 1979 album "Dream Police", which had lead singer Robin Zander, lead guitarist Rick Nielsen, and bassist Tom Petersson each singing a verse. The song did not go beyond a demo, but it was referenced in "High Priest of Rhythmic Noise", a track from 1980's "All Shook Up". "Position" was eventually re-recorded for this album, and features only Zander singing.
Document 15: Cheap Trick: Cheap Trick is an American rock band from Rockford, Illinois, formed in 1973. The band currently consists of vocalist Robin Zander, guitarist Rick Nielsen, bassist Tom Petersson and touring drummer Daxx Nielsen. Original drummer Bun E. Carlos stopped touring with the band in 2010 but remains a partner in their business organization.
ground_truth: yes