 Most of the album 's tracks are about rock and roll itself – Angus stated , " Certain songs just seem to come to life when you add that phrase " . However , other themes served as inspiration . " Money Made " is a criticism on how , according to Angus , in the US " everything is money these days " . " War Machine " was based on a documentary on Hannibal , which led to the conclusion that the military has not changed since Ancient Rome . " Wheels " tells about Johnson 's passion for motorcars . He described the album 's release as the " best one we 've done " , he felt that while Back in Black was great for its time , Black Ice shows the band 's versatility . Angus also said he admired the album 's diversity , saying " It is sufficiently varied to please people in varied moods " . 
