Question: What is the opening date of this recording studio opened by a rock and roll pioneer in Memphis, Tennessee, where Million Dollar Quarter was recorded?

Related documents: [0]  [DOC] "Million Dollar Quartet" is a recording of an impromptu jam session involving Elvis Presley, Jerry Lee Lewis, Carl Perkins, and Johnny Cash made on December 4, 1956, at the Sun Record Studios in Memphis, Tennessee. An article about the session was published in the "Memphis Press-Scimitar" under the title "Million Dollar Quartet". The recording was first released in Europe in 1981 as "The Million Dollar Quartet" with 17 tracks. A few years later more tracks were discovered and released as "The Complete Million Dollar Session". In 1990, the recordings were released in the United States as "Elvis Presley - The Million Dollar Quartet". This session is considered a seminal moment in rock and roll. [END] 
[1]  [DOC] Sun Studio is a recording studio opened by rock-and-roll pioneer Sam Phillips at 706 Union Avenue in Memphis, Tennessee, on January 3, 1950. It was originally called Memphis Recording Service, sharing the same building with the Sun Records label business. Reputedly the first rock and roll single, Jackie Brenston and his Delta Cats' "Rocket 88" was recorded there in 1951 with song composer Ike Turner on keyboards, leading the studio to claim status as the birthplace of rock & roll. Blues and R&B artists like Howlin' Wolf, Junior Parker, Little Milton, B.B. King, James Cotton, Rufus Thomas, and Rosco Gordon recorded there in the early 1950s. [END]  
Answer: January 3, 1950
January 3, 1950