Complex sentence: The song "Iron Man" was originally entitled "Iron Bloke"; upon hearing the main guitar riff for the first time, Osbourne remarked that it sounded "like a big iron bloke walking around".
Split into simpler sentences: The song "Iron Man" was originally entitled "Iron Bloke". Upon hearing the main guitar riff for the first time, Osbourne remarked that it sounded "like a big iron bloke walking around".