Stevie Ray Vaughan

Context: In September 1970, Vaughan made his first studio recordings with the band Cast of Thousands, which included future actor Stephen Tobolowsky. They recorded two songs, "Red, White and Blue" and "I Heard a Voice Last Night", for a compilation album, A New Hi, that featured various teenage bands from Dallas. In late January 1971, feeling confined by playing pop hits with Liberation, Vaughan formed his own band, Blackbird. After growing tired of the Dallas music scene, he dropped out of school and moved with the band to Austin, Texas, which had more liberal and tolerant audiences. There, Vaughan initially took residence at the Rolling Hills Country Club, a venue that would later become the Soap Creek Saloon. Blackbird played at several clubs in Austin and opened shows for bands such as Sugarloaf, Wishbone Ash, and Zephyr, but could not maintain a consistent lineup. In early December 1972, Vaughan left Blackbird and joined a rock band named Krackerjack; he performed with them for less than three months.  In March 1973, Vaughan joined Marc Benno's band, the Nightcrawlers, after meeting Benno at a jam session years before. The band featured vocalist Doyle Bramhall, who met Vaughan when he was twelve years old. The next month, the Nightcrawlers recorded an album at Sunset Sound Recorders in Hollywood for A&M Records. While the album was rejected by A&M, it included Vaughan's first songwriting efforts, "Dirty Pool" and "Crawlin'". Soon afterward, he and the Nightcrawlers traveled back to Austin without Benno. In mid-1973, they signed a contract with Bill Ham, manager for ZZ Top, and played various gigs across the South, though many of them were disastrous. Ham left the band stranded in Mississippi without any way to make it back home and demanded reimbursement from Vaughan for equipment expenses; Ham was never reimbursed.  In 1975, Vaughan joined a six-piece band called Paul Ray and the Cobras that included guitarist Denny Freeman and saxophonist Joe Sublett. For the next two-and-a-half years, he earned a living performing weekly at a popular venue in town, the Soap Creek Saloon, and ultimately the newly opened Antone's, widely known as Austin's "home of the blues". In late 1976, Vaughan recorded a single with them, "Other Days" as the A-side and "Texas Clover" as the B-side. Playing guitar on both tracks, the single was released on February 7, 1977. In March, readers of the Austin Sun voted them as Band of the Year. In addition to playing with the Cobras, Vaughan jammed with many of his influences at Antone's, including Buddy Guy, Hubert Sumlin, Jimmy Rogers, Lightnin' Hopkins, and Albert King.  Vaughan toured with the Cobras during much of 1977, but near the end of September, after they decided to strive for a mainstream musical direction, he left the band and formed Triple Threat Revue, which included singer Lou Ann Barton, bassist W. C. Clark, and drummer Fredde Pharaoh. In January 1978, they recorded four songs in Austin, including Vaughan's composition "I'm Cryin'". The thirty-minute audio recording marks the only known studio recording of the band. CANNOTANSWER

Question: what year was Stevie Ray Vaughan's 1st tour?
Answer: Vaughan toured with the Cobras during much of 1977,