Recently a friend of mine inquired if the ghazal Rang pairahan ka by Mehdi Hassan is based on any Hindustani raga.
The melodic contours here ally with Raga Dhanakoni Kalyan, a recent raga conceived by the late C.R. Vyas. The swaras are drawn from the melakarta Vachaspati. The raga is developed by eliminating the dhaivat entirely and deploying elements of the Kalyan raganga. The rishab is either omitted or rendered alpa in arohi movements.
Noodling around on YouTube I found another ghazal Ek khalish ko by Mehdi Hassan that co-opts the same theme. I am curious to know if Mehdi-sahab hit upon the melodic idea independently or if he absorbed it from someone else.
Also – Raga Krishna Kalyan composed by Ramashreya Jha “Ramrang” treads along similar lines (see Volume 4 of his Abhinav Geetanjali series), except that the rishab is freely deployed there in both arohi and avarohi directions.