The Rajasthan Express incorporated musicians from Qawwali, Muslim Roma and a brass section who had played in weddings and parades.

Ben Tzur wrote the songs, with Greenwood contributing guitar, bass, keyboards, ondes Martenot and programming.

Israeli composer Shye Ben Tzur, who had been living in India for over a decade, was contacted by the Radiohead guitarist Jonny Greenwood, who admired his music.

[3] Ben Tzur, Greenwood and the Radiohead producer Nigel Godrich set up a recording studio in Mehrangarh Fort in Rajasthan.

[3] Ben Tzur wrote the songs, with Greenwood contributing guitar, bass, keyboards, ondes Martenot and programming.

[3] According to Pitchfork, Junun incorporates "Bollywood-style brass exuberance, the devotional Qawwali music of Sufi Islam, and bowed-string instruments associated with the Manganiar community".

[8] Pitchfork wrote: "The ensemble's playing and [Ben Tzur's] compositions make Junun an easy stretch—though, crucially, not a condescending one—for listeners otherwise unfamiliar with the great variety of methods often obscured by 'world music' market-speak.

"[4] The Guardian wrote: "Greenwood contributes subtle embellishments – occasional electronic beats, as well as understated guitar and bass – rather than any scene-stealing showboating.