Question:  Hugo Ferreira and Glenn Gregory are both singers and what?

Context paragraphs:
Honeyroot: Honeyroot is an ambient dance collaboration between Glenn Gregory and Keith Lowndes, signed to the independent record label Just Music.

Tantric (band): Tantric is an American rock band from Louisville, Kentucky, United States.  The group was founded in 1999 by former Days of the New members Todd Whitener, Jesse Vest and Matt Taul (now all no longer with the band), and Hugo Ferreira.  Altogether Tantric has released six studio albums and one EP "Tantric" (2001), "After We Go" (2004), "The End Begins" (2008), "Broken Down...Live in the Poconos" (2008), "Mind Control" (2009), "37 Channels" (2013) and "Blue Room Archives" (2014)

The End Begins: The End Begins is the third studio album from American band Tantric.  It is the first one recorded without the band's original members Todd Whitener, Matt Taul, and Jesse Vest.  Vocalist Hugo Ferreira, the only remaining original member, was forced to scrap the original line-up's complete third album in favor of "The End Begins", an effort established by new members of the band in addition to Ferreira.  This is the only studio album to feature former Fuel drummer Kevin Miller.

Glenn Gregory: Glenn Peter Gregory (born 16 May 1958) is an English singer, songwriter, and multi-instrumentalist whose music career spans more than 30 years.  He came to prominence in the early 1980s as co-founder and lead singer of the new wave and synthpop band Heaven 17, which released six singles that entered the Top 40 charts in the United Kingdom during the 1980s, and 1990s, including "Temptation", "Come Live with Me", "Crushed by the Wheels of Industry", "Sunset Now", "This Is Mine", and "(We Don't Need This) Fascist Groove Thang" .

After We Go: After We Go is the second studio album by Louisville post-grunge band Tantric.  Released on February 24, 2004, it debuted at #56 on the Billboard Album Charts but quickly lost momentum due to the lack of a strong single.  Despite the lack of radio success, the album is considered a success by singer Hugo Ferreira because it fared extremely well through the medium of downloading.  "After We Go" would be Tantric's final album for Maverick.

Hugo Ferreira: Hugo Ferreira (born March 7, 1974) is a Portuguese-American African-born singer/songwriter musician.  He is best known for being the lead singer and songwriter for the American rock band Tantric.

Naked as Advertised: Naked as Advertised is the eighth studio album by the English synthpop band Heaven 17.  It was originally released in 2008, on the label Just Music, three years after their previous album, "Before After".  The album contained re-workings of tracks such as "Temptation" along with versions of Martyn Ware songs best known from his time with the Human League, including "Being Boiled" and "Empire State Human", as well as a cover of The Associates' hit "Party Fears Two".  Following the departure of Ian Craig Marsh in 2007, this is the first Heaven 17 album with the band consisting of the duo of Glenn Gregory and Ware.

Mark Tinley: Mark Ty-Wharton (born Mark Tinley; 18 March 1963) is a British music technologist, informal logician and public speaker who specialises in presentations using sound art.  He is best known for his work as a guitarist, programmer, sound engineer and record producer with Adamski, Duran Duran, TV Mania, Gary Numan, Glenn Gregory, The Dandy Warhols and others.

Heaven 17: Heaven 17 are an English new wave and synth-pop band that formed in Sheffield in 1980.  The band were a trio for most of their career, composed of Martyn Ware (keyboards), Ian Craig Marsh (keyboards) (both previously of the Human League) and Glenn Gregory (vocals).  Although most of the band's music was recorded in the 1980s, they have occasionally reformed to record and perform, playing their first ever live concerts in 1997.  Marsh left the band in 2007 and Ware and Gregory continued to perform as Heaven 17.

British Electric Foundation: B.E.F. (British Electric Foundation) was a band/production company formed by former Human League members Martyn Ware and Ian Craig Marsh, which became largely eclipsed by its best-known project Heaven 17 (with lead singer Glenn Gregory).

Supporting paragraphs: Hugo Ferreira Glenn Gregory
Answer: songwriter