For more than 30 years, Johnny Winter has been at the forefront of modern blues and blues-rock, and his new I'm A Bluesman disc, arriving June 15 from Virgin Records, figures to add to his Texas-sized reputation. For this release, Johnny has again paired with his long-time producer Dick Shurman (Robert Cray, Albert Collins, Roy Buchanan), as well as Tom Hambridge (Susan Tedeschi, George Thorogood). Backing him is his road-tested touring band of ace harmonica man James Montgomery, bassist …