In the spin-off of this book, Small Steps, it says that X-Ray's real name is Rex Alvin Washburn.
ray is piglatin
Rex
harry
it is xray
Rayon X
xray fish
Holes.
They are called "black holes".
The holes on your sneakers are called 'eyes'
In Marathi, x-ray is called 'ksh-kiran'
holes
Holes.
X-Ray got his nickname in the book "Holes" because he claims to have X-ray vision when it comes to finding things buried in the ground. His real name is Rex, but he prefers to be called X-Ray because of his talent for finding objects underground.
I do not know if they have a musical name but they are commonly just called Recorder Holes.
primary radiation