If You Knew Suzi... is the fifth regular studio album by Suzi Quatro, released at the end of 1978, but with a 1979 copyright date. By August 2012 this was still Quatro's highest-charting album in the United States (it peaked at number 37 on The Billboard 200).[4] The album also yielded Quatro's biggest US single hit, a duet with Chris Norman named "Stumblin' In" (which reached number 4 in both The Billboard Hot 100 and the Billboard Adult Contemporary charts.[4] It also had an advertising billboard on Sunset Boulevard. The credits show the album to be a multinational production: tracks were recorded in Cologne (Germany), Paris (France), and Glendale (California). It was then mixed in California and mastered in London to be distributed by a company based in New York City.