In my opinion, the best reason to watch 'Umrao Jaan' is for Rekha's stunning and outstanding performance.
Rekha plays Amiraan, a girl who is torn from her family, sold to Khanum (the owner of a brothel in Lucknow), and re-christened 'Umrao Jaan'. As she grows into a woman, Umrao becomes renowned for her beauty, dancing skills, and poetic/musical ability. But despite the fame, is she happy? This film is about her search for happiness, the challenges she face along the way, and the relationships she forms with others.
'Umrao Jaan' is a quiet, sad, contemplative film. It makes you think about what many women go through, and it makes you think about the repercussions of simple life choices. But it also has wonderful naachgaana to offer - the ghazals are simply beautiful, and Rekha's dancing is simply spellbinding. Her emotional (but very restrained), multi-layered performance also deserves a lot of applause. The rest of the cast is also very good, but Rekha is the highlight of this film.