Jō-ah-kee-no
Here's a breakdown:
* Jō: Pronounced like the "jo" in "joy"
* ah: Pronounced like the "a" in "father"
* kee: Pronounced like the "key" in "key"
* no: Pronounced like the "no" in "no"
It's important to note that the "ch" in "Gioachino" is pronounced like the "k" in "key" and not like the "ch" in "chair".