Professional singers can do it, they are called musicians. Someone who doesn't even know the most basic musical scores, or doesn't even know how to play an instrument, who only sings is not worthy of being called a singer.

Professionals are very strong in music theory, which is also the basic condition for making good music.

If I have to say it, the average person who plays music should be able to read the simplest musical notation. The music notation is a bit worse.

In many bands, the lead singer writes his own songs, and the guitarist writes his own solos. The arrangement and production are all done by myself. All this requires is knowledge of music theory. If they don’t even know music scores, they don’t deserve to be musicians. This is the most basic!

So every singer should be able to read staff and simplified music scores, and be familiar with music theory. Only the music created in this way has a soul, not an empty shell.