Bollywood songs (often termed filmi songs) are heard far beyond the borders of India. The lines of Bollywood songs are some of the most memorized and repeated expressions in India. Yet, since Bollywood has not been considered formal literature, the lyrics of the Bollywood songs have not been studied in an academic setting.
The language of the filmi songs can be complex. It is termed Hindi in India and Urdu in Pakistan. Many songs are saturated with Persian terms, others can be in shuddha Hindi. It is not uncommon now to see usage of English words. Several dialects have been used: Braj, Bhojpuri, Punjabi, Rajasthani. Occasionally a few lines in another Indian language (for example in Jya Jale), or even a foreign language are added for mystery.