My Fair Lady
The upper-class professor of phonetics, Henry Higgins, and his friend Colonel Pickering are walking through Covent Garden when they hear the 'curbstone English' of Eliza Doolittle, a cockney selling flowers on the street. Professor Higgins boasts that it would only take him six months to transform the flower-seller into a well-spoken society lady. Or at the very least into a proper shop assistant. Eliza notes this last comment - she'd much to prefer to work in a shop - and next day presents herself at the Professor's, asking for his help.
Many elocution lessons follow, and progress is painfully slow at first, but finally Eliza makes a breakthrough - singing 'The Rain in Spain Falls Mainly On the Plain' in a posh accent.
Professor Higgins decides that is time for Eliza to enter society. This, of course, is a triumphant success. But the Professor takes all the credit, overlooking all Eliza's hard work. Eliza is angered, and returns home. When she leaves, Professor Higgins begins to realize his true feelings for her.