In the meantime, Foreigner began work on the next album at Electric Lady Studios in New York City with producer Robert John "Mutt" Lange, engineered by Dave Wittman (currently with Trans-Siberian Orchestra). "4" (released in July 1981) contained the hits "Urgent" (which includes the famous Junior Walker sax solo), "Waiting for a Girl Like You", "Juke Box Hero" and "Break it Up". Before releasing albums of his own, Thomas Dolby played synthesizers on "4" (he contributed the signature synth sound on "Urgent" and played the intro to "Waiting for a Girl Like You"). "4" became Foreigners first and only No 1. album in the US, spending 10 weeks in that position, and peaked at No. 2 in Canada. It also became the band's break-through album overseas, reaching the Top 5 in the UK, Germany and Australia.