As a singer for years I felt and many I performed with considered having the words in front of you was a no no.
However as the memory has got worse I have had to turn to to the words on paper and have found that my performance has actually improved.
There was always a certain amount of tension
because of the fear of forgetting the words.
It is possible to see the words or the music
as well as keep some eye contact with the audience.
Afterall that is what you do when you sing the classics in a large choir.
We all have different abilities and short comings so our approaches will all be diferent and who is to say what is the right one.
Cousin Ken