Question: Which artist also had a solo career, Jeff Martin or Mark Rankin?
Context: "Oh Mother" is a song recorded by American singer Christina Aguilera for her fifth studio album, "Back to Basics" (2006).  The song was released on November 23, 2007 by RCA Records as the fourth and final single from the album in European territories, while "Slow Down Baby" was serviced as the final single in Oceania.  It was written by Aguilera, Derryck Thornton, Mark Rankin, Liz Thornton, Christophe Barratier, Bruno Coulais and Kara DioGuardi.  Production was done by Big Tank and Q, with L Boggie credited as co-producer and Aguilera serviced as additional producer. Live in Dublin (2007) is a live album by Canadian singer/songwriter Jeff Martin.  The album is a complete recording of a live performance which included many songs written by The Tea Party, numerous covers (complete, and partial within other songs), as well as Martin's solo compositions. Mark Rankin is a Grammy-winning British record and mixing engineer and music producer, who began his career in 2004 as a house engineer at The Exchange studios.  He is a frequent collaborator of music producer Paul Epworth.  Rankin's credits include critically acclaimed albums by Adele, Queens of the Stone Age, Foster the People, Florence and the Machine and Bloc Party. Mark Rankin Herring (born September 25, 1961) is an American lawyer serving as the 47th and current Attorney General of Virginia.  He is a member of the Democratic Party.  Previously, he served in the Senate of Virginia since a 2006 special election.  He represented the 33rd district, made up of parts of Fairfax and Loudoun counties. Jeffrey Scott Martin (born October 2, 1969 in Windsor, Ontario) is a Canadian guitarist and singer-songwriter best known for fronting the rock band The Tea Party.  Martin began his career as a solo artist in October 2005, when The Tea Party went on hiatus. Jessica Rankin (born 1971, Sydney) is an Australian artist who lives and works in New York.  She has participated in numerous group exhibitions in the US, Europe and Australia.  Recent solo exhibitions include White Cube, London (2007), PS1 Contemporary Arts Center, New York (2006) and Franklin Artworks, Minneapolis (2005).  Rankin is best known for her organdy 'embroidered paintings' as well as her drawings, watercolors, and editioned prints, sometimes linked to her larger scale works.  Rankin's father is also a successful artist David Rankin.  Her mother was poet and playwright Jennifer Rankin and her step-mother is author and poet Lily Brett.  Rankin shares her studio with her partner, also a celebrated artist, Julie Mehretu.  Rankin is represented by Christian Haye of The Project gallery in the USA and in 2007 began to exhibit with Jay Jopling at the White Cube art gallery in the UK. Voodoo Highway is the second album of the band Badlands.  After the first Badlands album, drummer Eric Singer left the band to join KISS, and was replaced by drummer Jeff Martin, who had previously sung lead vocals in the bands Surgical Steel and Racer X.  Badlands bandmates Greg Chaisson and Jeff Martin later played together in the bands Blindside Blues Band and RedSea. Mark Rankin was lead vocalist with Scottish rock band Gun, who were best known for their cover of "Word Up! ", originally by Cameo.  The single was taken from the album "Swagger", and was released in 1994.  Other singles were "Better Days", "Taking on the World" and "Steal Your Fire". Jeffery Louis Martin is an American musician, singer and drummer who has sung for the bands Surgical Steel, Racer X, Leatherwolf, and played drums for the bands Badlands, Blindside Blues Band, and Red Sea.  Jeff Martin played drums for Paul Gilbert, George Lynch, Michael Schenker, Dokken and P.K. Mitchell.  He also played drums in Surgical Steel before switching to lead vocals.  He has released a solo album in 2006 entitled "The Fool", featuring the guitar talents of Paul Gilbert and Michael Schenker and has also sung backing vocals for Judas Priest and The Scream. Jeff Martin 777 was a rock band from Perth, Western Australia.  The band's name was inspired by Jeff Martin's study of the occult, specifically the work of Aleister Crowley.  Martin formed the band with former Sleepy Jackson members Malcolm Clark and Jay Cortez in 2010, after the demise of his previous band The Armada.  The band ended in 2012 after the re-activation of Martin's former group The Tea Party in 2011.
Answer: Jeffrey Scott Martin