In August and September 1979, the Clash recorded "London Calling". Produced by Guy Stevens, a former A&amp;R executive who had worked with Mott the Hoople and Traffic, the double album was a mix of punk rock, reggae, ska, rockabilly, traditional rock and roll and other elements possessed of an energy that had hardly flagged since the band's early days and more polished production. The title of the track also happened to be heavily influenced by the BBC World Service call signal and the panic that resulted in the Three Mile Island nuclear scare. It is regarded as one of the greatest rock albums ever recorded. Its final track, a relatively straightforward rock and roll number sung by Mick Jones called "Train in Vain", was included at the last minute and thus did not appear in the track listing on the cover. It became their first US Top 40 hit, peaking at number 23 on the "Billboard" chart. In the UK, where "Train in Vain" was not released as a single, "London Calling"'s title track, stately in beat but unmistakably punk in message and tone, rose to number 11—the highest position any Clash single reached in the UK before the band's break-up.