BACK FOR MORE Ratt plays a sizzling set at Anaheim House of Blues to kick off the annual NAMM convention in California By Gerry Gittelson Metal Sludge Editor at large   ANAHEIM — With the annual NAMM convention starting, the evening festivities kicked off with a sold-out concert Thursday featuring Ratt, Warrant and Stonebreed at House of Blues, and wow what a spectacular performance by all three bands. Ratt put on an 80-minute set[…]