This is originally a qawali by Nusrat Fateh Ali Khan and the tune of its mehendi version is more or less the same… but in a fast version… thats how we sing this song at any mehendi function… You can get some idea of the tune from this youtube video… make it a faster version for the mehendi song… it will sound goood
We try to give more emphasis on hoootings and sounds like
Dama Dum Mast Qalander… HOAY
Sakhi shabaz qalandar … HOAY
Ali dum dum de andher … HOAY
Ho laal meri, ho laal meri
(dhol beat)