Question: What do Anthony Green and Serj Tankian have in common?

Context paragraphs:
Elect the Dead Symphony: Elect the Dead Symphony is the first live album by System of a Down frontman Serj Tankian.  It is available in CD, CD/DVD, LP, and Digital Download formats.  It features the Auckland Philharmonia Orchestra at the Auckland Town Hall in Auckland, New Zealand.  Orchestral arrangements were by John Psathas.  Material for the performance is from Tankian's solo debut, "Elect the Dead" with some additional previously unreleased songs.

Something Else (Tech N9ne album): Something Else is the thirteenth studio album by American rapper Tech N9ne.  It was released on July 30, 2013, by Strange Music and RBC Records.  The album has broken up into three portions – Earth, Water & Fire.  Production on the album was handled during 2012 to 2013, primarily by frequent collaborator Seven, among others such as Young Fyre, Drumma Boy, and Fredwreck.  The album features guest appearances from B.o.B, Big K.R.I.T., CeeLo Green, The Doors, The Game, Kendrick Lamar, Serj Tankian, T-Pain, Trae tha Truth and Wiz Khalifa, among others including several artists from Tech N9ne's Strange Music imprint.

Empty Walls: "Empty Walls" is a song by musician Serj Tankian.  The song was released as the first official single and first track off of Tankian's debut solo album "Elect the Dead".  The song has been described as a "traditionally pummeling rocker".

Cool Gardens: Cool Gardens is a poetry book by the lead singer of the band System of a Down, Serj Tankian.  It was published by MTV Books and was released on October 1, 2002.  It is a collection of seven to eight years of Tankian's reflections on life, and features artwork by fellow Angeleno, Sako Shahinian.  The poetry, like the songs of System of a Down, consists of a reflection of societies and people's wrongs.  It portrays what people do to themselves and the control others try to hold over them.

Serj Tankian: Serj Tankian (Western Armenian: Սերժ Թանկեան , ] ; born August 21, 1967) is a Lebanese-born Armenian-American singer-songwriter, composer, multi-instrumentalist, record producer, poet, and political activist with Armenian descent.  He is best known as the lead vocalist, songwriter, keyboardist, and occasional live rhythm guitarist of the metal band System of a Down, formed in 1994.

Sky Is Over: "Sky Is Over" is a song by Serj Tankian.  The song was released as the second single from Tankian's debut solo album "Elect the Dead".  The song has charted on both the Modern Rock Tracks and the Mainstream Rock Tracks in the US.

Elect the Dead: Elect the Dead is the debut album by rock musician Serj Tankian, lead singer and founding member of Armenian-American metal quartet System of a Down.  It was released on October 22, 2007.  Alongside Tankian appears Armenian-American coloratura Ani Maldjian, drummers John Dolmayan from System of a Down and B. Brain Mantia of Primus and Guns N' Roses, Dan Monti on guitars, as well as a string section featuring Antonio Pontarelli.

Enter the Chicken: Enter the Chicken is the fourteenth studio album by musician Buckethead.  The album was released on October 25, 2005 by Serj Tankian's label Serjical Strike.  It has 11 songs, two of which are less than twenty seconds long.  It contains appearances from such artists as Saul Williams, Maximum Bob, Efrem Schulz and Serj Tankian.

Serart: Serart is a collaboration album by two international Armenian musicians: Serj Tankian ("Ser-"), lead singer of System of a Down, and folk multi-instrumentalist Arto Tunçboyacıyan ("-art").  It was the first release on Tankian's own label, Serjical Strike Records.

Anthony Green (musician): Anthony Green (born April 15, 1982) is an American musician from Doylestown, Pennsylvania.  He is currently the lead singer of Circa Survive and Saosin, while also maintaining a solo career.  He was previously in the bands The Sound of Animals Fighting, Audience of One, Jeer at Rome, High and Driving, and Zolof the Rock and Roll Destroyer.  Green is known for his high tenor vocal range.

Supporting paragraphs: Anthony Green (musician) Serj Tankian
Answer: singer