question: Are Gaz Coombes and Petri Lindroos both vocalists?
answer: yes
context: Title: Petri Lindroos
  Passage: Petri Lindroos (born 10 January 1980 in Espoo, Finland) is a melodic death/folk metal guitarist and vocalist.  He is currently the lead vocalist in Ensiferum and, prior to this, was a founder and lead vocalist for Norther.
  Title: Bad Blood (Supergrass song)
  Passage: "Bad Blood" is the second single from British rock group Supergrass' sixth album, "Diamond Hoo Ha".  It was released on 17 March 2008, which was one week before the album's release date.  The song is about a rough night out in Reykjavík, Iceland, as Gaz Coombes explains;
  Title: The Hotrats
  Passage: The Hotrats (originally the Diamond Hoo Ha Men) is a cover band formed by Gaz Coombes and Danny Goffey as a side-project from their main band Supergrass.  The band is named after Frank Zappa's album "Hot Rats".  The duo recorded a set of covers with producer Nigel Godrich for an album entitled "Turn Ons" in the vein of David Bowie's "Pin Ups" which was released in early 2010.  They performed a short UK tour which included the Reading and Leeds Festivals.
  Title: The Jennifers
  Passage: The Jennifers were a short-lived British rock group formed at Wheatley Park School and featuring vocalist Gaz Coombes, guitarist Nic Goffey, drummer Danny Goffey and bassist Andy Davies.  Danny and Nic Goffey are the sons of former BBC Top Gear presenter and motoring journalist Chris Goffey.
  Title: Aleksi Sihvonen
  Passage: Aleksi Sihvonen is the current vocalist for the Finnish band Medicated.  He replaced Norther's vocalist Petri Lindroos in 2009, until the group disbanded in 2012.  He was also the former guitarist and vocalist of Imperanon.
  Title: Matador (Gaz Coombes album)
  Passage: Matador is the second solo album by British musician Gaz Coombes.  Recorded at Coombes' home studio and Courtyard Studios in Oxfordshire, it was released on 26 January 2015 on his record label Hot Fruit Recordings via Caroline International.  Coombes himself produced the album and it features appearances by Ride drummer Loz Colbert and Charly Coombes.  The album charted #18 on the UK Albums Chart.  It was nominated for the 2015 Mercury Music Prize.
  Title: I Should Coco
  Passage: I Should Coco is the debut studio album by English alternative rock band Supergrass, released through Parlophone in May 1995.  Supergrass were formed in 1993 by Gaz Coombes, Mick Quinn and Danny Goffey and they released their debut single from the album, "Caught by the Fuzz", in May 1995 on the small independent local label Backbeat Records and was re-released with Parlophone.  The title of the album is cockney rhyming slang for "I should think so".
  Title: Gaz Coombes
  Passage: Gareth "Gaz" Michael Coombes (born 8 March 1976 in Oxford) is an English musician and singer-songwriter, best known as the lead vocalist and guitarist of the English alternative rock band Supergrass.  He first entered the music scene aged sixteen as the lead singer of the band The Jennifers which featured Supergrass bandmate Danny Goffey.  Coombes was noticeable for his large sideburns during the 1990s.
  Title: Supergrass discography
  Passage: The discography of Supergrass, an English alternative rock band, consists of six studio albums, three extended plays, two compilation albums, 26 singles and 24 music videos.  They were formed in 1993 by Gaz Coombes, Mick Quinn and Danny Goffey.  Rising to prominence during the Britpop era in the mid-1990s with their single "Alright", they were joined by Rob Coombes in 2002 (keyboards) until their demise on 11 June 2010.
  Title: Here Come the Bombs
  Passage: Here Come the Bombs is the debut solo album of former Supergrass front man Gaz Coombes, who performed all of the instruments on the album.  It was released on 21 May 2012 by record label Hot Fruit Recordings.  It charted at #54 on the UK Albums Chart.
citations: Gaz Coombes Petri Lindroos