Billie Holiday's Prime?

I'm thinking Columbia 1933 -1944...

I'm listening to it and I'm not sure...

The 50's maybe?

With Teddy Wilson or with Lester Young.  Even when her voice declined in the 50s, she was still an excellent singer.  The earlier stuff had the combination of the voice and the singer.

Good stuff onhwy61. 

Any specific albums/recordings that you'd recommend?

TIA

singers like her/her style don't depend so much on age, clarity, whatever you call "vocal cord youth" and strength. It's the soulfulness, maturity, routine, balance, etc.  that that improve the quality and richness of her sound over time.