"Mere sapno ki rani" is a popular Hindi

Hindi

Standard Hindi, or more precisely Modern Standard Hindi, also known as Manak Hindi , High Hindi, Nagari Hindi, and Literary Hindi, is a standardized and sanskritized register of the Hindustani language derived from the Khariboli dialect of Delhi...

 song from the 1969 Bollywood

Bollywood

Bollywood is the informal term popularly used for the Hindi-language film industry based in Mumbai , Maharashtra, India. The term is often incorrectly used to refer to the whole of Indian cinema; it is only a part of the total Indian film industry, which includes other production centers producing...

 movie Aradhana. The song was composed by Sachin Dev Burman

Sachin Dev Burman

Sachin Dev Burman , also credited as Burman da, Kumar Sachindra Dev Barman, Sachin karta or S. D. Burman, was one of the most famous music composers for Hindi movies and a Bengali singer and composer. His son Rahul Dev Burman also achieved great success as a Bollywood music director in his own...

 and performed by Kishore Kumar

Kishore Kumar

Kishore Kumar , born Abhas Kumar Ganguly, was an Indian film playback singer and an actor who also worked as lyricist, composer, producer, director, screenwriter and scriptwriter.Kishore Kumar was one of India's greatest performers of the late 20th century...

. In the film, Rajesh Khanna

Rajesh Khanna

Rajesh Khanna is an Indian actor of from Hindi films, and has been Hindi film producer and an Indian politician....

, the male protagonist sings the song atop an open jeep

Jeep

Jeep is an automobile marque of Chrysler . The first Willys Jeeps were produced in 1941 with the first civilian models in 1945, making it the oldest off-road vehicle and sport utility vehicle brand. It inspired a number of other light utility vehicles, such as the Land Rover which is the second...

 virtually chasing the heroine Sharmila Tagore

Sharmila Tagore

Sharmila Tagore is an Indian film actress. She has won National Film Awards and Filmfare Awards for her performances.She has led the Indian Film Censor Board from October 2004 till March 2011...

 who was aboard the toy train in Darjeeling (Darjeeling Himalayan Railway

Darjeeling Himalayan Railway

The Darjeeling Himalayan Railway, nicknamed the "Toy Train", is a narrow gauge railway from New Jalpaiguri to Darjeeling in West Bengal, run by the Indian Railways....

). R. D. Burman composed the song after his father, S.D. Burman, became too ill to finish the film's music. The song became a superhit in India.