Having grown up with musician parents, I really don't remember my first awareness of music. But I've had so many of those magical moments, and they are among my favorite memories.
Awaking in the middle of the night to hear Jim Mageean and Johnny Collins singing in my living room; that was amazing. (I was ten and had the flu; it was a rather otherworldly experience)
The first time I heard a bombarde and knew I HAD to have one. I felt like a rat following the pied piper; I followed the sound until I found what was making it, then harrassed the player into teaching me to play and telling me where I could buy one.
The time I spent an hour in a room with a harpist (the nerdiest guy in high school), listening to him tune and practice his harp. What a magical time.
But to top it all, the time I participated in the All-Eastern Chorus and discovered 400 other people who walked around singing to themselves all day and night long. Who sang in the elevators, on the streets, hanging out of hotel windows at 2am...who barely ate because they couldn't sing while they ate. Now that was amazing.
Outside of choral groups, I haven't "clicked" while singing with many others, mostly due to lack of opportunity. It's a big empty space waiting to be filled.