I always wonder when people were first exposed to jazz.
My grandmother was a great singer and pianist.
She taught me Pennies from Heaven in the swimming pool when I was 6 years old.
Years later in high school I saw a poster advertising an audition for a gig in South Beach singing standards with a vibes player and a sequencer! For the audition I had to learn a bunch of standards, and the vibes player gave me a tape with Ella and Sarah and Billie etc. to learn the songs from. A few days into rehearsing for the audition I realized "ah, that's what I should do with my voice!" and I started looking for college Jazz programs instead of Musical Theater. (saved!)
I didn't start singing jazz until 2010. I was active in musical theater back in the mid 60's. A business and family got in the way of that career. Then one day in 2010 after an encounter with my daughters guitar teacher she encouraged me to follow my dream and I did.
I started listening in at a gypsy jam when I was 63. At about the third one, I was sitting behind the fiddle player, whistling along to myself (I thought). She turned and said "you're pretty good, come on up and join us". A month or so later, someone called a tune and said "Can anyone sing this?", and after everyone looked blank I said I'd give it a try. Within months I was going to camps, sitting in at other jams and taking lessons, and since I've retired it's become my main gig. I've done it before, but I need to thank that fiddle player again.