India is in the middle of a literacy explosion. Better schooling and the spread of cheap Hindi media outlets has led to a boom in literacy in all Indian languages, and that provides consumers with a growing choice of market languages. Literacy fuels economic growth.

According to the latest census in 2011, 74% of Indians, aged 7 and above, are literate. The next question is:  just how literate are they?

About half of Hindi speakers can’t even read a newspaper headline, according to the Indian Institute of Management in Ahmedabad. Clearly, there are many who have not advanced beyond a basic familiarity with the alphabet.

So despite improvements, about 400 million so-called “literates” can’t read their way out of a paper bag. Add on the quarter billion more who can’t read by any measure and you’ve got two-thirds of a billion people who still need to learn to read.

Roving National Geographic Explorer Ken Banks thought that the massive audiences for Hindi cinema would make a great classroom for Hindi literacy. He thought that Bollywood could promote Hindi literacy with Same Language Subtitling — or “SLS” — that is, captioning text on-screen to match the audio. When translating sound to text in the same language, Banks says “what you hear is what you read. SLS suggests subtitling the lyrics of existing film songs and music videos on television, in the language in which they are sung. Hindi songs subtitled in Hindi. Tamil song subtitled in Tamil, and so on in every one of India’s 22 official languages. In other words, Bollywood film songs marry karaoke to produce mass literacy.”

SLS is literacy magic. Studies prove that once it appears on screen, readers find it irresistible. Even early readers can’t help but try to follow along, and in the process they improve their reading skills. Since viewers love to learn song lyrics and are curious to know their meaning, the building of reading skills becomes fun instead of frustrating.

Banks notes that weak readers normally face a high motivational barrier to keep reading in the face of tedious print. But song lyrics are light, repetitive and easy to remember. They make for the perfect language lesson — simple phrases repeated and anticipated.

Independent studies show that even 30 minutes of weekly SLS exposure over a couple of years more than doubles the number of functional readers in primary schools in India. And it turns out that song lyrics are a kind of gateway drug when it comes to literacy addiction. Studying song lyrics encourages new readers to start reading the newspapers.

A special added bonus is that women are big Bollywood fans, and SLS is helping to reduce the abysmally low literacy rate for women in India, which runs about 65% according to the 2011 census.

Hooray for Bollywood!