Watch: Salim-Sulaiman's 25-year musical journey is chronicled in 'Shukranallah'

Salim-Sulaiman, the musical duo who have being composing melodies for Bollywood for two-and-a-half decades, just released the trailer for their musical journey 'Shukranallah' on YouTube.The musical duo, who shot to fame composing  for films like Chak De! India (2007), Rab Ne Bana Di Jodi (2008) and Fashion(2008), gained international recognition with their performance during the opening of the FIFA World Cup.The musical Shukranallah, also the name of the popular song composed by the siblings in the film Kurbaan (2009), follows Salim-Sulaiman as they travel across the world to perform in concerts with fans cheering them through.It is through this journey that we not only get closer to Salim-Sulaiman's music but also learn about their struggles and apprehensions regarding following their dreams. The film makes them more personable, showing their dreams and struggles, rather than portraying them as musical gods for whom the whole world is a stage. The film will be available exclusively on the iTunes store.Here is the brilliant monochrome trailer of the musical film with plenty of slow-mo shots: