While "singer" is a common word, adding "-ist" to the end doesn't create a valid English word.
You might be thinking of:
* Singer: This is the standard term for someone who sings.
* Vocalist: This is a more formal word for a singer, often used in musical contexts.
If you're looking for a specific type of singer, you could use descriptive terms like "opera singer," "rock singer," "folk singer," etc.