Barbra Streisand's journey from funny girl to full-fledged auteur blazed a trail followed by generations of pop hopefuls. Broadway belters like Idina Menzel and Kristin Chenoweth, cucumber-cool crooners like Michael Bublé and Josh Groban, and pop divas like Céline Dion and Whitney Houston all took cues from Streisand's feisty spirit and emotionally charged performances.