I have a problem right off the bat, with this statement:
To be specific, what three pieces of music are guaranteed to put a smile on your face and make you feel happy and relaxed?
In my opinion, and for my musical tastes, "the best music I’ve ever heard", is often music that does not "put a smile on my face, makes me happy and relaxed".
A lot of the music that I love can be: challenging to listen to, dark, atonal, not convey happy or relaxing feelings. I love music that can be cathartic to listen to.
I also love some music that can be happy and joyous, but I don’t rate it any higher because of those attributes.
I don’t have any idea how anyone could narrow down the best music that ever heard (whatever that means to them) to only 3. You have to know that is a ridiculous ask, right? I listen to: prog-rock, jazz, contemporary avant-garde classical music, and I could easily list a dozen in each genre that I would consider equals in their greatness.
I’ll make one choice per genre:
Elliott Carter - Concerto for Orchestra (1969) / Dark, complex, intense
Yes - Close to the Edge (1972) / Intense and sometimes a bit dark, but ends on an up, hopeful feeling. Based on the book "Siddhartha" by Hermann Hesse, it depicts a man’s search for enlightenment.
John Coltrane - A Love Supreme (1965) /

