I studied world music in school....
the best female singers IMHO..
USA- Madonna, Aretha Franklin, Carole King, Pat Benatar, Stevie Nicks,
India/Pakistan- Lata Mangeshkar and Asha Bosle
Arab world - Oum Khalthoum, Fairouz and Haifa Wehbe
but my all time favorite singer is the Queen of Turkish pop music:
She is the BIGGEST SINGER in Greece and Turkey, and collaborated with many other singers in Turkey such as Tarkan, Gulshen, and Sertab Erener
JUST WATCH THE MUSIC VIDEO BELOW YOU WILL GET UP AND WANT TO START DANCING!!:
The song is called "Shinanay" by Sezen Aksu