Question: What role have both Matthew Tuck and Frank Iero performed in musical groups?
Related documents: [0]  [DOC] Frank Anthony Iero, Jr. (born October 31, 1981) is an American musician who was the rhythm guitarist and backup vocalist of the rock band My Chemical Romance and post-hardcore band Leathermouth. He has a solo punk rock project titled Frank Iero and the Patience. He released an album under the previous name of frnkiero andthe cellabration titled "Stomachaches" which was released on August 26, 2014. The first single off the album, called "Weighted", premiered on BBC Radio One on July 8, 2014. [END] 
[1]  [DOC] Matthew "Matt" Tuck (born 20 January 1980) is a Welsh musician. He is the lead vocalist and rhythm guitarist in the Welsh heavy metal band Bullet for My Valentine. He and the other 3 members of his old band founded "Jeff Killed John" in 1998, but after bassist Nick Crandle left in 2003, the band was renamed to Bullet for My Valentine. He is also a singer and guitarist in the supergroup AxeWound, which was formed in 2012. He also plays piano, drums, keyboard, and harmonica. He did a collaboration with Max Cavalera (Soulfly, Cavalera Conspiracy, ex-Sepultura) and with Apocalyptica in the song "Repressed". [END] 
Answer: 
rhythm guitarist
rhythm guitarist