Listen to 3 x 7 = 21 online. 3 x 7 = 21 is an English language song and is sung by Jewel King. 3 x 7 = 21, from the album The Best Of Bob Dylan's Theme Time Radio Hour Vol 2, was released in the year 2008. The duration of the song is 1:54. Download English songs online from JioSaavn.