Craig Gruber ( June 22 , 1951 -- May 5 , 2015 ) was an American rock bassist , best known as the original bassist in Rainbow and most recently was a member for the band Zvekan .
Craig Gruber ( June 22 , 1951 -- May 5 , 2015 ) was an American rock bassist and musician . He was best known as the original bassist in the English band band Rainbow .