American lyricist and composer Bert Kalmar, active during the early 20th century, was a significant figure in popular music and vaudeville. He is best known for his prolific songwriting partnership with composer Harry Ruby, creating numerous hits for Broadway shows and Hollywood films. Their collaborations produced enduring standards like "Three Little Words" and "Nevertheless (I'm in Love with You)," solidifying Kalmar's legacy in the Great American Songbook.