Question: Which nine-time Grammy Award-winning gospel group helped found the National Quartet Convention?

Context paragraphs:
Tye Tribbett: Tyrone "Tye" Tribbett (born January 26, 1976) is an American gospel music singer, songwriter, keyboardist, choir director and founder of the Grammy-nominated and Stellar Award-winning gospel group Tye Tribbett & G.A. (short for 'Greater Anointing.')

Thy Kingdom Come: Thy Kingdom Come is the eighth solo album from Grammy Award-winning gospel singer CeCe Winans.  It was released on April 1, 2008 and debuted at number 57 on the "Billboard" 200 chart.  The album received the Best Pop/Contemporary Gospel Album award at the 51st Grammy Awards in 2009.  It also reached #12 on the R&B/Hip Hop chart and #1 on the Gospel Album Charts.

Singing News Fan Awards: The Singing News Fan Awards is an annual award ceremony held on the Wednesday afternoon program of the National Quartet Convention and honors the achievements of professional Southern Gospel artists, songwriters and DJ's.

O'Landa Draper: O'Landa Draper (September 29, 1963 – July 21, 1998) was a Grammy Award-winning Gospel music artist.  He was the founder of the Associates Choir and is considered to be one of the top gospel artists of the 1990s.  Draper was nominated for the Grammy Award, Stellar Awards and the Dove Award multiple times.

Stephen Underwood: Stephen Underwood (born December 13, 1975 in Bakersfield, California) is an American drummer who has worked with several artists and musicians.  He is best known for being drummer and vocalist for the Southern Gospel quartet The Lighthouse Boys.  Stephen also spent two years with Standard Warrior Band from Standard Middle School in Bakersfield, CA, and a stent from 1996-2001 with the Watchmen Quartet on events like The Great Western Quartet Convention and The WSGMA Memorial Day and Labor Day Concerts.  In 1999 Stephen was on stage with the Watchmen Quartet as they backed up the Legendary James Blackwood at the Great Western Quartet Convention at the Selland Arena in Fresno, CA.  Stephen is also a studio drummer and currently records and performs with The Lighthouse Boys, Red Letter Edition and more recently Southern Gospel band Blue Diamonds from Long Beach, CA

National Quartet Convention: The first National Quartet Convention was held in 1957.  J. D. Sumner, Cecil Blackwood and James Blackwood of The Blackwood Brothers were the founders of the famous National Quartet Convention formerly held in Memphis, Tennessee.  The National Quartet Convention featured all the major gospel groups at a three-day event at the Ellis Auditorium in Memphis, Tennessee.  After the first couple of years, the NQC was moved to Birmingham, Alabama in 1959 and Atlanta, Georgia in 1960.  It returned to Memphis in 1961 and was drawing annual crowds of 20,000 by the mid-1960s.  Sumner bought the convention in 1971 and moved it to Nashville, Tennessee in 1972, where it remained until 1993.  The National Quartet Convention was held in Nashville, Tn.  through 1993.  After 1993, it was moved to a new home, Louisville, Kentucky.  In 2014 the convention moved to Pigeon Forge, Tennessee.

Singing News Fan Awards for Favorite Group: The Singing News Favorite Group award is awarded in the yearly Singing News Fan Awards ceremony held at the National Quartet Convention every September.  It is awarded to the group which readers of the Singing News Magazine judge to be the best group on the road.

The Blackwood Brothers: The Blackwood Brothers are an American southern gospel quartet.  They are nine-time Grammy Award-winning pioneers of the Christian music industry.

The Blind Boys of Alabama: The Blind Boys of Alabama are a five-time Grammy Award-winning gospel group who first sang together in 1939.  The Blind Boys have toured for seven decades, and created an extensive discography.  In 2016 the on-stage configuration of the group consists of eight people: four blind singers—Jimmy Carter, Ben Moore, Eric “Ricky” McKinnie, Paul Beasley - guitarist and musical director Joey Williams, and a keyboard player, a bass player, and a drummer.

Karen Clark Sheard: Karen Clark-Sheard (born Karen Valencia Clark; November 15, 1960) also known as "The Maestris Of Gospel" is an American gospel four-time Grammy Award-winning singer, musician, and songwriter.  The youngest daughter of pioneering gospel choral director Mattie Moss Clark, Sheard began her career as a member of the legendary Grammy Award-winning female gospel group The Clark Sisters.  She is the mother of contemporary gospel singer and actress Kierra "Kiki" Sheard.

Supporting paragraphs: National Quartet Convention The Blackwood Brothers
Answer: The Blackwood Brothers