“Crazy Train” began with Randy Rhoads’ signature guitar riff. He played the riff for bassist Bob Daisley, who helped Rhoads flesh out the chords. With Rhoads’ guitar feeding back through his amplifier ...

A malfunctioning piece of equipment in the studio could spell disaster for the day’s session, but in 1980, it helped inspire one of Ozzy Osbourne’s biggest hits of his solo career, “Crazy Train.” From ...