"Why This Kolaveri Di" (English: Why This Killing rage, Girl?) is a song from the soundtrack of the 2012 Tamil psychological thriller film, 3. The song is written and sung by Dhanush, and composed by Anirudh Ravichander.

The song was officially released on 16 November 2011 and instantly became viral on social networking sites for its quirky "Tanglish" (portmanteau word of Tamil and English) lyrics. Soon, the song became the most searched YouTube video in India and an internet phenomenon across Asia. Within a few weeks, YouTube honoured the video with a '"Recently Most Popular" Gold Medal award and "Trending" silver medal award for receiving a large number of hits in a short time. Following its huge success and nationwide popularity Dhanush, the singer of the original track was invited by then Prime Minister Dr. Manmohan Singh as a "Guest of Honour".

According to composer Anirudh Ravichander, 3's director Aishwarya Rajinikanth Dhanush wanted a light-hearted song about love failure. Ravichander quickly composed the tune in about 10 minutes. Dhanush then began working on the lyrics, which he completed in about 20 minutes of brainstorming. The first line he sang was "Why This Kolaveri?" which means "Why do you have this murderous rage against me girl?" The question, however, is not intended seriously.

In a party to The Times of India, Dhanush said: "When I was writing down the lyrics, I kept in mind all the English words that are used in the Tamil vocabulary. Words like I, you, me, how, why, cow. I just framed them into sentences and thats how I came up with the song." Dhanush sang the song in broken English, as a Tamil person might if his knowledge of English was limited. The song is also called a 'Soup' song, where 'Soup' is a colloquial Tamil word which refers to young men experiencing love failure after a beautiful relationship.

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Wikipedia