Question: What Lyricist is known for collaborations on musicals such as "Rex" and "Fiddler on the Roof"? 
Sentence (from "Sheldon Harnick"): Sheldon Harnick (born April 30, 1924) is an American lyricist best known for his collaborations with composer Jerry Bock on musicals such as "Fiddler on the Roof".
Relevant evidence: Yes