Question: Which violinist worked with the American rock band "Seventh Key" who also worked at Tulsa Philharmonic?

Context paragraphs:
Sanford Allen: Sanford Allen (born 1939) is an American classical violinist.  At ten, he began studying violin at the Juilliard School of Music and continued at the Mannes School of Music under "Vera Fonaroff".  In 1962, shortly after winning the inaugural Young Concert Artists competition, he became the first full-time African-American violinist with the New York Philharmonic.  After leaving the Philharmonic in 1977, Allen pursued a career as a soloist, teacher, and adviser on the arts.  He also worked extensively recording film music.

Chris Alexander (editor): Chris Alexander is a Toronto-based film critic, director, and freelance writer, and the current managing editor for the horror website Shock Till You Drop.  Alexander is a film critic with the Toronto Film Critics Association and has written for the free daily newspaper "Metro News".  In 2010 he became the editor-in-chief of "Fangoria" magazine, a position he held until September 2015, when he stepped down in favor of pursuing his directorial and music career.  Alexander also stated that he intended to continue to contribute editorial content but that he also intended to focus on "Delirium," a Full Moon Features magazine he launched with filmmaker Charles Band.  He has previously written for "Rue Morgue" and also worked as editor for "Kiss: Monster", the official magazine of the rock band Kiss.  Alexander has also worked as a radio personality for AM 640 on "The John Oakley Show" from 2004 to 2009 and for "Rue Morgue Radio" from 2004 to 2007.  He has composed music for several horror films and productions such as the radio drama series "Fangoria's Dreadtime Stories".  In 2006, Alexander participated in the "Raging Boll" stunt in Vancouver, boxing genre filmmaker Uwe Boll.

Tim Kelleher (musician): Timothy "Tim" Kelleher (born October 4, 1980) is an American musician best known for touring with the American rock band Thirty Seconds to Mars from 2007 to 2011, and most recently was a member of the American rock band Filter from 2013 to 2015.  He was one of the founding members of My Darling Murder, a metal band formed with friends Andy Gerold and Elias Mallin.  Kelleher has also worked with Fear and the Nervous System, 8mm, Wired All Wrong, and My Darling Murder.

Melvins: The Melvins are an American rock band that formed in 1983 in Montesano, Washington.  They have mostly performed as a trio, as well as a quartet with two drummers in recent years.  Since 1984, vocalist and guitarist Buzz Osborne and drummer Dale Crover have been constant members.  The band was named after a supervisor at a Thriftway in Montesano, Washington, where Osborne also worked as a clerk.  "Melvin" was despised by other employees, and the band's members felt it to be an appropriately ridiculous name.  Their early work was key to the development of both grunge and sludge metal.

Mary Ramsey: Mary Ramsey (born 24 December 1963), a resident of Buffalo, New York, is a member of folk rock duo John & Mary and lead singer and violinist for the American alternative rock band 10,000 Maniacs.  Ramsey has also worked with other well-known artists such as Jackson Browne, Goo Goo Dolls, Billy Bragg, Warren Zevon, Alex Chilton and Ani DiFranco.

Seventh Key: Seventh Key is an American rock band formed by Mike Slamer of City Boy and Streets and Billy Greer of Streets and Kansas.  The current lineup consists of Greer on bass and lead vocals, Slamer on guitar, bass, and keyboard, Pat McDonald on drums, David Manion on keyboard, and Terry Brock on guitar and backing vocals.  The band had two previous drummers, Chet Wynd (2001) and Jamie Thompson (2004), as well as guest appearances by David Ragsdale of Kansas on the violin (2005) and Johnny Greer on the mandolin (2005).

Susan Voelz: Susan Voelz (born Susana Maria Voelz) is an American musician.  A Grammy Award-nominated vocalist, violinist, and composer.  She is a member of the alternative rock band, Poi Dog Pondering.  She has also worked with a long list of famous musicians. <ref name="Official site/bio1"> </ref>

David Ragsdale: David Lasater Ragsdale, (born April 3, 1958) has been the violinist for Kansas from 1991 to 1997 and from 2006 to the present.  He started violin at the age of three.  After studies with classical teachers and a stint at the Tulsa Philharmonic, Ragsdale's violinist duties took him out of the largely classical area and into rock and roll.

Seventh Key (album): Seventh Key is the first album by the American rock group Seventh Key.

Billy Greer: Billy Greer (born January 26, 1952) is the current bass guitarist for the band Kansas.  He joined the band in 1985 in time for the Power album.  He had previously worked with keyboardist/vocalist Steve Walsh in the band Streets, and works with his own band Seventh Key when not performing with Kansas.  He also was a member of the brief 2009 Kansas side project "Native Window" along with Kansas members Phil Ehart, Richard Williams, and David Ragsdale.

Supporting paragraphs: Seventh Key David Ragsdale
Answer: David Ragsdale