Barbara Cook (October 25, 1927 – August 8, 2017) was an American singer and actress who first came to prominence in the 1950s as the lead in the original
Plain and Fancy (1955),
Candide (1956) and
The Music Man (1957) among others, winning a
Tony Award for the last. She continued performing mostly in theatre until the mid-1970s, when she began a second career as a cabaret and concert singer. She also made numerous recordings.
During her years as Broadway’s leading
ingénue Cook was lauded for her excellent
lyric soprano voice. She was particularly admired for her vocal agility, wide range, warm sound, and emotive interpretations. As she aged her voice took on a darker quality, even in her
head voice, that was less prominent in her youth.
 At the time of her death, Cook was widely recognized as one of the "premier interpreters" of musical theatre songs and standards, in particular the songs of composer
Stephen Sondheim. Her subtle and sensitive interpretations of American popular song continued to earn high praise even into her eighties.
 She was named an honoree at the 2011
Kennedy Center Honors.