To find out how many jazz classes are given, we can divide the total number of classes by the number of different types of classes.
The dance school conducts a total of 950 classes, and there are 5 types of classes (jazz, tap, hip-hop, ballet, and lyrical).
We can use the following calculation:
\[ \text{Number of classes of each type} = \frac{\text{Total number of classes}}{\text{Number of types of classes}} = \frac{950}{5} = 190 \]
Therefore, the number of jazz classes given is 190.