In addition, the band's slow, blues-driven riffs were seen by some as outmoded against the rising generation of metal bands such as Judas Priest and Motörhead. After the albums Technical Ecstasy and Never Say Die! were not universally critically well received, Iommi and Butler decided that Sabbath needed a fresh start so, in the summer of 1979, they replaced Osbourne with Ronnie James Dio, the former vocalist for Rainbow. With Dio, Black Sabbath produced Heaven and Hell, an album that attempted to update Black Sabbath's sound for the 1980s and include the soaring vocals that characterised the NWOBHM (New wave of British heavy metal) scene.