The spontaneous mash-up, which took place at a Universal Music Group event Berlin, saw the 55-year-old "Summer of '69" hitmaker on the guitar and Bieber, 21, handling the vocals, including Ludacris' verse, reported Entertainment Weekly.
The "Where Are You Now" singer was there promoting his new album, which is slated for release on November 13.
Adam's new album, "Get Up", will be out October 16.
Bieber's latest single, "What Do You Mean?" recently debuted at the top of the Billboard Hot 100 chart, making him the youngest male artist to debut at No. 1.