What are your top 3 favorite female singers?

This does seem to be a theme occasionally and one that I enjoy.

Adele makes me wanna vomit.

I’m sure that there are a variety of legal medications available for people who enjoy her music.

Lucinda Williams

Joni Mitchel

(now it gets tough!)

Gonna go with Barb Jungr mainly for her Dylan covers.

Honorable mention:

Patricia Barber

Eva Cassidy

Emmylou

Iris Dement

Gillian Welch

Betty Levette

Flora Purim

Bonnie Raitt

Margo Price

Chrissie Hynde

Margo Timmins

Janis and Grace

Lydia Pence

….and many more

Kate Bush 

Chelsea Wolfe 

Marley Monroe

Jane Relf

Margot Timmons

Carly Simon

hm;  Eva Cassidy 

Naturally, you meant to type "WHO" not "what" in your post.  People are generally referred to as WHO.

If you mean ladies who can actually SING as opposed to belting out pop garbage:

Linda Ronstadt

Aretha

Ella

Cheers!