"Quien sera?" (Luis Demetrio - Pablo Beltran Ruiz) was composed as a Mexican mambo in 1953 and issued as an instrumental by Pablo Beltran and his Orchestra.

The Dean Martin (Crocetti) number fifteen cover single with English lyrics by Normal Gimbel came out a year later on the album "Hey Brother, Pour the Wine". The release hit the top ten in the U.K.