Question: Who is the lead vocalist and guitarist for the heavy metal band Machine Head, Robb Flynn or Rome Ramirez ?

Context paragraphs:
Unto the Locust: Unto the Locust is the seventh full-length studio album by American groove metal band Machine Head, released in Australia on September 23, in the UK on September 26 and worldwide on September 27, 2011.  The album was produced and mixed by Robb Flynn, and it was the band's highest charting album ever, charting at 22 on the "Billboard" 200, until their following release "Bloodstone & Diamonds" charted at 21.  "Unto the Locust" was recorded in Green Day's Jingletown Studios.  On June 14, 2011, Machine Head released the advance mix of their album track "Locust", which was included on the 2011 Mayhem Festival iTunes sampler.  This would be Machine Head's last studio album with co-founder and bassist Adam Duce before he was fired due to "ongoing differences" with the band on February 11, 2013.  It has sold over 100,000 copies in the United States.  At just under 49 minutes long it is the band's shortest album released to date.

Aesthetics of Hate: "Aesthetics of Hate" is a song by heavy metal band Machine Head from their sixth studio album "The Blackening".  Written by Machine Head vocalist and guitarist Robert Flynn, the song is a retaliation to an article written by William Grim.  Grim wrote that late guitarist Dimebag Darrell was "an ignorant, barbaric, untalented possessor of a guitar", among other comments which angered Flynn deeply enough to write the song.  It was nominated for Best Metal Performance at the 50th Grammy Awards.

Through the Ashes of Empires: Through the Ashes of Empires is the fifth studio album by groove metal band Machine Head.  The band moved away from the nu metal genre featured on their previous two albums, and towards the style of their debut "Burn My Eyes" and their second album "The More Things Change..." It was released in the UK, Europe and Australia on the Roadrunner Records International label on December 16, 2003.  At this stage, Machine Head still did not have an American record deal, having parted ways with Roadrunner Records US after the "Supercharger" album was released.  "Through The Ashes of Empires" was such a success that Roadrunner Records US, in an unprecedented move, quickly offered Machine Head a new contract and the album finally reached North America on April 20, 2004.

Machine Head (band): Machine Head is an American heavy metal band from Oakland, California.  Formed on October 12, 1991, the group was founded by vocalist/guitarist Robb Flynn and bassist Adam Duce.  The current lineup of the band comprises Flynn, drummer Dave McClain, guitarist Phil Demmel and bassist Jared MacEachern.  Machine Head is one of the pioneering bands in the new wave of American heavy metal.

Roadrunner United: Roadrunner United was a project organized by the heavy metal record label Roadrunner Records to celebrate its 25th anniversary.  It culminated in an album released worldwide on October 11, 2005, entitled "The All-Star Sessions".  Four "team captains" were chosen to lead 57 artists from 45 past and present Roadrunner bands, and produce and oversee the album's 18 tracks: then (now former) Slipknot drummer Joey Jordison, Trivium frontman and guitarist Matt Heafy, Fear Factory guitarist Dino Cazares, and Machine Head frontman and guitarist Robb Flynn.  The unprecedented project was the brainchild of Roadrunner UK General Manager Mark Palmer and Roadrunner USA VP of A&R Monte Conner.  The album project was coordinated by Lora Richardson and was mixed by Colin Richardson and Andy Sneap.  "The All-Star Sessions" spawned one single and music video ("The End").  The DVD included with the CD purchase is a documentary of the "Making Of" the songs.  It features the sessions of the four team captains making their songs.

Machine Fucking Head Live: Machine Fucking Head Live is the second live album from the American heavy metal band Machine Head.  And it is the final release to include bassist Adam Duce who was fired, due to ongoing differences on February 11, 2013.  The album was released on November 13, 2012, under Roadrunner Records.  It was recorded at Central, Manchester on December 6, 2011 (except Locust & Halo recorded at SECC, Glasgow on December 5, 2011).  "The Head Cases [Machine Head's nickname for their fans] have been so intense on this tour cycle that we had to start capturing the shows, especially with technology making it so much easier to record," said frontman Robb Flynn.  "We culled some of the best nights where the band and crowd were on fire and made a badass, nearly two-hour, double live album, which is a great documentation of where the band is at, 18 years deep."

Burn My Eyes: Burn My Eyes is the debut studio album by American groove metal band Machine Head, released on August 9, 1994 by Roadrunner Records.  The album's themes generally tie into the social disorder and corresponding inner tension that the band was exposed to in their native Oakland, California, reflected in Robb Flynn's lyrics, such as the Los Angeles Riots of 1992 and the Waco Siege of 1993.  The album shipped over 400,000 copies worldwide, becoming Roadrunner Records's best selling debut album until the release of Slipknot's debut album.

Robb Flynn: Robert Conrad "Robb" Flynn (born Lawrence Matthew Cardine; July 19, 1967) is the lead vocalist and guitarist for the heavy metal band Machine Head.  Flynn formed the band along with Adam Duce, Logan Mader and Tony Costanza after leaving Bay Area thrash band Vio-Lence.

Phil Demmel: Phil Demmel (born April 2, 1967) is the lead guitarist for American heavy metal band Machine Head, and is currently their longest running member in that position.  He was also a founding member of Vio-lence, which also included Machine Head guitarist/vocalist Robb Flynn.  Demmel was also a member of Torque.

Rome Ramirez: Roman René Ramírez (born June 11, 1988 in Fremont, California), better known as Rome Ramirez or simply Rome, is an American singer and guitarist best known for playing with Eric Wilson from Sublime and Josh Freese from The Vandals in the band Sublime with Rome.  The lineup initially featured original Sublime drummer Bud Gaugh before his departure in 2011.  Despite participation by Gaugh and Wilson, the family of deceased Sublime member Bradley Nowell legally challenged the use of the Sublime name by the surviving members.  Nowell had actually registered the trademark "Sublime" under his own name prior to his death, and had sole ownership at the time of his death.  The lineup featuring Rome, Wilson and Bud Gaugh released their debut album "Yours Truly" on July 12, 2011.

Supporting paragraphs: Robb Flynn Rome Ramirez
Answer: Robert Conrad "Robb" Flynn